Initial import

.gitignore

@@ -0,0 +1,25 @@
+# Nix build outputs
+/result
+/result-*
+/nix-build*
+*.drv
+*.drv.chroot
+
+# Local Nix/dev environment
+/.direnv/
+/.devenv/
+.envrc.local
+
+# Editors and OS junk
+.DS_Store
+Thumbs.db
+*.swp
+*.swo
+*~
+.idea/
+.vscode/
+
+# Generic temp/log files
+*.log
+*.tmp
+*.bak

README.md

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+# Brain i.MX28 NixOS setup
+
+This repo reconstructs a NixOS build environment for SHARP Brain
+(i.MX28 / armv5). It includes local clones of the upstream Brain
+projects and a Nix-based build configuration.
+
+## Contents
+- `sources/` clones:
+  - `buildbrain` (u-boot-brain, brainlilo, image scripts)
+  - `linux-brain` (kernel)
+  - `sheevaplug-nix` (reference for armv5 NixOS)
+- `docs/brain-bootflow.md` - boot chain + SD layout notes
+- `docs/nixos-build.md` - build steps
+- `nix/` - NixOS config and build expressions
+- `patches/` - u-boot extlinux patch
+- `bootfiles/` - files copied to the SD FAT partition (BrainLILO, u-boot)
+
+## Quick start
+1. Read `docs/brain-bootflow.md`.
+2. Follow `docs/nixos-build.md` to build U-Boot and the SD image.

bootfiles/loader/README.txt

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+Place the model-specific U-Boot binary here.
+
+PW-SS6 / PW-SH6:
+- Use pwsh6_defconfig from u-boot-brain
+- Name the file: gen3_6.bin
+
+The mapping comes from sources/buildbrain/brainlilo/models.h.

docs/brain-bootflow.md

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+# Brain (i.MX28) Linux boot flow notes
+
+This is a consolidated boot-flow summary based on local sources:
+- buildbrain (boot image scripts, BrainLILO, u-boot-brain)
+- linux-brain kernel tree
+- brainux wiki pages (build + USB gadget)
+
+## 1) Boot chain overview
+1. i.MX28 ROM loads Windows CE from internal storage (vendor default).
+2. Windows CE launches the BrainLILO app from the SD card.
+3. BrainLILO selects a model-specific U-Boot binary from the SD card
+   and jumps to it (soft reset / memory remap).
+4. U-Boot loads the Linux kernel (zImage) + DTB from SD/eMMC
+   and boots Linux with `bootz`.
+
+Key locations:
+- BrainLILO loads from `\\Storage Card\\loader\\<model>.bin`
+  (see `sources/buildbrain/brainlilo/models.h`).
+- Boot image creation logic is in `sources/buildbrain/image/build_image.sh`.
+
+## 2) SD card layout (buildbrain convention)
+From `sources/buildbrain/image/build_image.sh`:
+- Partition 1: FAT32 (~64 MiB)
+  - `zImage` and DTBs (`imx28-pwsh*.dtb`)
+  - `nk/` and `loader/` containing U-Boot binaries
+  - BrainLILO app directory (Windows CE): `アプリ/Launch Linux`
+    - `AppMain.exe` (exeopener)
+    - `AppMain_.exe` (BrainLILO.exe)
+    - `*.dll`, `index.din`, `AppMain.cfg`
+- Partition 2: ext4 rootfs
+
+## 3) U-Boot behavior (brain_mx28_common.h)
+`sources/buildbrain/u-boot-brain/include/configs/brain_mx28_common.h`:
+- `bootorder=emmc sd`, `sddev=1` (SD), `emmcdev=0` (eMMC)
+- Loads `zImage` + `fdt_file` from FAT (`fatload`), then `bootz`
+- Optional `uEnv.txt` import on SD/eMMC via `preboot`
+- Default DTB is set by defconfig, e.g. `CONFIG_DEFAULT_FDT_FILE=imx28-pwsh5.dtb`
+
+## 4) Kernel/DTB
+`linux-brain` provides the kernel and DTBs:
+- Kernel: `arch/arm/boot/zImage`
+- DTB: `arch/arm/boot/dts/imx28-pwsh{1..7}.dtb`, `imx28-pwa7200.dtb`, etc.
+- Base DTS: `arch/arm/boot/dts/imx28-brain.dtsi`
+
+Kernel version in this tree: `5.4.149` (see `sources/linux-brain-brain/Makefile`).
+
+## 5) USB gadget (RNDIS)
+Default `imx28-brain.dtsi` sets USB controller to host mode:
+- `usb@80080000 { dr_mode = "host"; }`
+
+Brainux wiki describes switching to gadget mode by changing
+`dr_mode = "peripheral"` and then enabling RNDIS via configfs.
+A reference script/service exists in:
+- `sources/buildbrain/os-brainux/override/usr/bin/enable_rndis_gadget`
+- `sources/buildbrain/os-brainux/override/lib/systemd/system/rndis_gadget.service`
+
+## 6) Recovery / USB boot
+Buildbrain uses `u-boot.sb` for i.MX28 USB recovery mode (`uuu`).
+See `sources/buildbrain/README.md` and `sources/buildbrain/Makefile`.

docs/nixos-build.md

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+# NixOS on SHARP Brain (i.MX28) - build guide
+
+This directory contains a Nix-based build setup for Brain (armv5). It
+assumes the following repositories exist in `sources/`:
+- `sources/linux-brain-brain` (kernel)
+- `sources/buildbrain` (boot tooling + u-boot-brain submodule)
+
+See `docs/brain-bootflow.md` for the boot chain details.
+
+## 0) Model and DTB name
+Pick your Brain model and DTB name from:
+- `sources/linux-brain-brain/arch/arm/boot/dts/`
+
+Examples:
+- PW-SH5 -> `imx28-pwsh5.dtb`
+- PW-SH6 -> `imx28-pwsh6.dtb`
+
+DTB selection is done by U-Boot via the `fdtfile` environment variable,
+which is set from `CONFIG_DEFAULT_FDT_FILE` in each defconfig. Build the
+matching U-Boot defconfig for your model (pwshX / pwa7X00).
+
+## 1) U-Boot with extlinux support (fork + patch)
+Patch file:
+- `patches/u-boot-brain-extlinux.patch`
+
+Apply it to your fork of `brain-hackers/u-boot-brain` and build
+for your model defconfig (pwshX / pwa7X00).
+
+Nix build helper (cross-compiles to armv5):
+
+```sh
+nix-build nix/uboot.nix -A pwsh6
+```
+
+Output:
+- `result/u-boot.bin`
+
+Rename it for BrainLILO:
+- `gen3_6.bin` (PW-SH6)
+
+The mapping is defined in:
+- `sources/buildbrain/brainlilo/models.h`
+
+## 2) Prepare bootfiles/ (FAT partition contents)
+The latest BrainLILO release has already been downloaded and extracted to:
+- `bootfiles/アプリ/BrainLILO/`
+
+Create the following layout in `bootfiles/` (PW-SH6 example):
+
+```
+bootfiles/
+  loader/
+    gen3_6.bin
+  nk/                     # optional
+  アプリ/BrainLILO/
+    AppMain.exe
+    BrainLILO.dll
+    BrainLILODrv.dll
+    index.din
+```
+
+Notes:
+- BrainLILO release binaries are from:
+  https://github.com/brain-hackers/brainlilo/releases
+- If you prefer the buildbrain layout (`アプリ/Launch Linux`), use
+  `sources/buildbrain/image/build_image.sh` as the reference.
+
+## 3) Build the NixOS SD image
+Build from this repo root:
+
+```sh
+nix-build nix/brain-system.nix -A config.system.build.sdImage
+```
+
+The image will be in:
+- `result/sd-image/brain-nixos-*.img.bz2`
+
+Flash it to SD:
+
+```sh
+bzcat result/sd-image/brain-nixos-*.img.bz2 > /dev/sdX
+```
+
+## 4) Boot
+- Insert the SD card into the Brain.
+- Run BrainLILO from Windows CE (SD card app list).
+- U-Boot loads extlinux from the ext4 root partition.
+
+## 5) USB gadget (optional)
+To use USB Ethernet gadget:
+- Change DTB `dr_mode` from `host` to `peripheral` in `imx28-brain.dtsi`.
+- Enable a configfs RNDIS gadget (see `docs/brain-bootflow.md`).

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1769900590,
+        "narHash": "sha256-I7Lmgj3owOTBGuauy9FL6qdpeK2umDoe07lM4V+PnyA=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "41e216c0ca66c83b12ab7a98cc326b5db01db646",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-25.11",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,48 @@
+{
+  description = "NixOS for SHARP Brain (i.MX28)";
+
+  inputs = {
+    # Use the latest stable NixOS release channel (non-unstable).
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-25.11";
+  };
+
+  outputs = { self, nixpkgs, ... }:
+  let
+    buildSystem = "x86_64-linux";
+    crossSystem = import ./nix/platform.nix { lib = nixpkgs.lib; };
+
+    pkgsHost = import nixpkgs {
+      localSystem = buildSystem;
+    };
+
+    pkgsKernelCross = import nixpkgs {
+      localSystem = buildSystem;
+      crossSystem = crossSystem;
+    };
+
+    pkgsKernelNative = import nixpkgs {
+      localSystem = crossSystem;
+    };
+  in {
+    nixosConfigurations.brain-cross = nixpkgs.lib.nixosSystem {
+      system = buildSystem;
+      specialArgs = {
+        pkgsKernel = pkgsKernelCross;
+      };
+      modules = [
+        {
+          nixpkgs.crossSystem = crossSystem;
+        }
+        ./modules/brain.nix
+        ./modules/sd-image/sd-image-brain.nix
+      ];
+    };
+
+    packages.${buildSystem} = {
+      sdImage = self.nixosConfigurations.brain-cross.config.system.build.sdImage;
+      ubootPwsh6 = (import ./nix/uboot.nix { pkgs = pkgsHost; }).pwsh6;
+      pkgsKernelCross = pkgsKernelCross;
+      pkgsKernelNative = pkgsKernelNative;
+    };
+  };
+}

modules/brain.nix

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+{ lib, pkgs, pkgsKernel, ... }:
+let
+  brainKernel = import ../nix/brain-kernel.nix { pkgs = pkgsKernel; };
+in {
+  # =========================================================================
+  #      Board specific configuration
+  # =========================================================================
+
+  boot.kernelPackages = pkgsKernel.linuxPackagesFor brainKernel;
+
+  boot.kernelParams = [
+    "console=ttyAMA0,115200n8"
+    "console=tty1"
+    "rootwait"
+    "fbcon=font:ProFont6x11"
+  ];
+
+  boot.supportedFilesystems = lib.mkForce [
+    "vfat"
+    "ext4"
+    "btrfs"
+  ];
+
+  hardware.deviceTree = {
+    enable = true;
+    name = "imx28-pwsh6.dtb";
+  };
+
+  # Firmware bundle; keep the same set as before.
+  hardware.firmware = lib.mkForce (
+    with pkgs; [
+      linux-firmware
+      intel2200BGFirmware
+      rtl8192su-firmware
+      rt5677-firmware
+      zd1211fw
+      # alsa-firmware builds a host tool (tobin) that runs during build.
+      pkgs.buildPackages.alsa-firmware
+    ]
+    ++ lib.optional (pkgs.stdenv.hostPlatform.isAarch32 || pkgs.stdenv.hostPlatform.isAarch64)
+      raspberrypiWirelessFirmware
+    ++ lib.optionals (builtins.hasAttr "rtl8723bs-firmware" pkgs && lib.versionOlder brainKernel.version "4.13") [
+      pkgs."rtl8723bs-firmware"
+    ]
+    ++ lib.optionals (builtins.hasAttr "openelec-dvb-firmware" pkgs) [
+      pkgs."openelec-dvb-firmware"
+    ]
+    ++ lib.optionals (builtins.hasAttr "rtlwifi_new-firmware" pkgs) [
+      pkgs."rtlwifi_new-firmware"
+    ]
+  );
+
+  powerManagement.cpuFreqGovernor = "ondemand";
+
+  # =========================================================================
+  #      Base NixOS Configuration
+  # =========================================================================
+
+  networking.hostName = "brain";
+  networking.useDHCP = true;
+
+  services.openssh = {
+    enable = lib.mkDefault true;
+    settings = {
+      X11Forwarding = lib.mkDefault true;
+      PasswordAuthentication = lib.mkDefault true;
+    };
+    openFirewall = lib.mkDefault true;
+  };
+
+  nix.settings = {
+    experimental-features = [ "nix-command" "flakes" ];
+  };
+
+  system.stateVersion = "25.11";
+}

modules/sd-image/sd-image-brain.nix

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+# Generate sdImage for SHARP Brain (i.MX28)
+{ config, lib, pkgs, ... }:
+let
+  bootfiles = builtins.path {
+    path = ../../bootfiles;
+    name = "brain-bootfiles";
+  };
+in {
+  imports = [
+    ./sd-image.nix
+  ];
+
+  boot.kernelParams = [
+    "console=ttyAMA0,115200n8"
+    "console=tty1"
+    "rootwait"
+    "fbcon=font:ProFont6x11"
+  ];
+
+  boot.loader = {
+    grub.enable = false;
+    generic-extlinux-compatible.enable = true;
+  };
+
+  fileSystems = lib.mkForce {
+    "/boot" = {
+      device = "/dev/disk/by-label/${config.sdImage.firmwarePartitionName}";
+      fsType = "vfat";
+      # Alternatively, this could be removed from the configuration.
+      # The filesystem is not needed at runtime, it could be treated
+      # as an opaque blob instead of a discrete FAT32 filesystem.
+      options = [ "nofail" ];
+    };
+    "/" = {
+      device = "/dev/disk/by-label/NIXOS_SD";
+      fsType = "ext4";
+    };
+  };
+
+  sdImage = {
+    imageBaseName = "brain-nixos";
+    firmwarePartitionName = "BOOT";
+    firmwareSize = 64; # MiB
+
+    populateFirmwareCommands = ''
+      # Copy Brain boot assets (BrainLILO, u-boot loader, etc.)
+      cp -R ${bootfiles}/. firmware/
+      ${config.boot.loader.generic-extlinux-compatible.populateCmd} -c ${config.system.build.toplevel} -d ./firmware
+    '';
+
+    populateRootCommands = ''
+      mkdir -p ./files/boot
+    '';
+  };
+}

modules/sd-image/sd-image.nix

@@ -0,0 +1,303 @@
+# `nixos/modules/installer/sd-card/sd-image.nix` patched for Lichee Pi 4A
+#
+#  https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/installer/sd-card/sd-image.nix
+#
+# chainsx provides a U-Boot where normal Distro Boot(extlinux.conf) works well. but:
+#     1. it requires the first partition to be /boot and the second partition to be /.
+#     1. it requires the the partition table to be GPT instead of MBR/DOS.
+#
+# To resolve the above issues, we need to patch the sd-image.nix. that's what this file does.
+#
+# This module creates a bootable SD card image containing the given NixOS
+# configuration. The generated image is MBR partitioned, with a FAT
+# /boot/firmware partition, and ext4 root partition. The generated image
+# is sized to fit its contents, and a boot script automatically resizes
+# the root partition to fit the device on the first boot.
+#
+# The firmware partition is built with expectation to hold the Raspberry
+# Pi firmware and bootloader, and be removed and replaced with a firmware
+# build for the target SoC for other board families.
+#
+# The derivation for the SD image will be placed in
+# config.system.build.sdImage
+
+{ config, lib, pkgs, modulesPath, ... }:
+
+with lib;
+
+let
+  rootfsImage = pkgs.callPackage "${modulesPath}/../lib/make-ext4-fs.nix" ({
+    inherit (config.sdImage) storePaths;
+    compressImage = config.sdImage.compressImage;
+    populateImageCommands = config.sdImage.populateRootCommands;
+    volumeLabel = "NIXOS_SD";
+  } // optionalAttrs (config.sdImage.rootPartitionUUID != null) {
+    uuid = config.sdImage.rootPartitionUUID;
+  });
+in
+{
+  imports = [
+    (mkRemovedOptionModule [ "sdImage" "bootPartitionID" ] "The FAT partition for SD image now only holds the Raspberry Pi firmware files. Use firmwarePartitionID to configure that partition's ID.")
+    (mkRemovedOptionModule [ "sdImage" "bootSize" ] "The boot files for SD image have been moved to the main ext4 partition. The FAT partition now only holds the Raspberry Pi firmware files. Changing its size may not be required.")
+    "${modulesPath}/profiles/all-hardware.nix"
+  ];
+
+  options.sdImage = {
+    imageName = mkOption {
+      default = "${config.sdImage.imageBaseName}-${config.system.nixos.label}-${pkgs.stdenv.hostPlatform.system}.img";
+      description = lib.mdDoc ''
+        Name of the generated image file.
+      '';
+    };
+
+    imageBaseName = mkOption {
+      default = "nixos-sd-image";
+      description = lib.mdDoc ''
+        Prefix of the name of the generated image file.
+      '';
+    };
+
+    storePaths = mkOption {
+      type = with types; listOf package;
+      example = literalExpression "[ pkgs.stdenv ]";
+      description = lib.mdDoc ''
+        Derivations to be included in the Nix store in the generated SD image.
+      '';
+    };
+
+    firmwarePartitionOffset = mkOption {
+      type = types.int;
+      default = 8;
+      description = lib.mdDoc ''
+        Gap in front of the /boot/firmware partition, in mebibytes (1024×1024
+        bytes).
+        Can be increased to make more space for boards requiring to dd u-boot
+        SPL before actual partitions.
+
+        Unless you are building your own images pre-configured with an
+        installed U-Boot, you can instead opt to delete the existing `FIRMWARE`
+        partition, which is used **only** for the Raspberry Pi family of
+        hardware.
+      '';
+    };
+
+    firmwarePartitionID = mkOption {
+      type = types.str;
+      default = "0x2178694e";
+      description = lib.mdDoc ''
+        Volume ID for the /boot/firmware partition on the SD card. This value
+        must be a 32-bit hexadecimal number.
+      '';
+    };
+
+    firmwarePartitionName = mkOption {
+      type = types.str;
+      default = "FIRMWARE";
+      description = lib.mdDoc ''
+        Name of the filesystem which holds the boot firmware.
+      '';
+    };
+
+    rootPartitionUUID = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      example = "14e19a7b-0ae0-484d-9d54-43bd6fdc20c7";
+      description = lib.mdDoc ''
+        UUID for the filesystem on the main NixOS partition on the SD card.
+      '';
+    };
+
+    firmwareSize = mkOption {
+      type = types.int;
+      # As of 2019-08-18 the Raspberry pi firmware + u-boot takes ~18MiB
+      default = 30;
+      description = lib.mdDoc ''
+        Size of the /boot/firmware partition, in megabytes.
+      '';
+    };
+
+    populateFirmwareCommands = mkOption {
+      example = literalExpression "'' cp \${pkgs.myBootLoader}/u-boot.bin firmware/ ''";
+      description = lib.mdDoc ''
+        Shell commands to populate the ./firmware directory.
+        All files in that directory are copied to the
+        /boot/firmware partition on the SD image.
+      '';
+    };
+
+    populateRootCommands = mkOption {
+      example = literalExpression "''\${config.boot.loader.generic-extlinux-compatible.populateCmd} -c \${config.system.build.toplevel} -d ./files/boot''";
+      description = lib.mdDoc ''
+        Shell commands to populate the ./files directory.
+        All files in that directory are copied to the
+        root (/) partition on the SD image. Use this to
+        populate the ./files/boot (/boot) directory.
+      '';
+    };
+
+    postBuildCommands = mkOption {
+      example = literalExpression "'' dd if=\${pkgs.myBootLoader}/SPL of=$img bs=1024 seek=1 conv=notrunc ''";
+      default = "";
+      description = lib.mdDoc ''
+        Shell commands to run after the image is built.
+        Can be used for boards requiring to dd u-boot SPL before actual partitions.
+      '';
+    };
+
+    compressImage = mkOption {
+      type = types.bool;
+      default = true;
+      description = lib.mdDoc ''
+        Whether the SD image should be compressed using
+        {command}`zstd`.
+      '';
+    };
+
+    expandOnBoot = mkOption {
+      type = types.bool;
+      default = true;
+      description = lib.mdDoc ''
+        Whether to configure the sd image to expand it's partition on boot.
+      '';
+    };
+  };
+
+  config = {
+    fileSystems = {
+      "/boot/firmware" = {
+        device = "/dev/disk/by-label/${config.sdImage.firmwarePartitionName}";
+        fsType = "vfat";
+        # Alternatively, this could be removed from the configuration.
+        # The filesystem is not needed at runtime, it could be treated
+        # as an opaque blob instead of a discrete FAT32 filesystem.
+        options = [ "nofail" "noauto" ];
+      };
+      "/" = {
+        device = "/dev/disk/by-label/NIXOS_SD";
+        fsType = "ext4";
+      };
+    };
+
+    sdImage.storePaths = [ config.system.build.toplevel ];
+
+    system.build.sdImage = pkgs.callPackage ({ stdenv, dosfstools, e2fsprogs,
+    mtools, libfaketime, util-linux, zstd }: stdenv.mkDerivation {
+      name = config.sdImage.imageName;
+
+      nativeBuildInputs = [ dosfstools e2fsprogs libfaketime mtools util-linux ]
+      ++ lib.optional config.sdImage.compressImage zstd;
+
+      inherit (config.sdImage) imageName compressImage;
+
+      buildCommand = ''
+        mkdir -p $out/nix-support $out/sd-image
+        export img=$out/sd-image/${config.sdImage.imageName}
+
+        echo "${pkgs.stdenv.buildPlatform.system}" > $out/nix-support/system
+        if test -n "$compressImage"; then
+          echo "file sd-image $img.zst" >> $out/nix-support/hydra-build-products
+        else
+          echo "file sd-image $img" >> $out/nix-support/hydra-build-products
+        fi
+
+        root_fs=${rootfsImage}
+        ${lib.optionalString config.sdImage.compressImage ''
+        root_fs=./root-fs.img
+        echo "Decompressing rootfs image"
+        zstd -d --no-progress "${rootfsImage}" -o $root_fs
+        ''}
+
+        # Gap in front of the first partition, in MiB
+        gap=${toString config.sdImage.firmwarePartitionOffset}
+
+        # Create the image file sized to fit /boot/firmware and /, plus slack for the gap.
+        rootSizeBlocks=$(du -B 512 --apparent-size $root_fs | awk '{ print $1 }')
+        firmwareSizeBlocks=$((${toString config.sdImage.firmwareSize} * 1024 * 1024 / 512))
+        imageSize=$((rootSizeBlocks * 512 + firmwareSizeBlocks * 512 + gap * 1024 * 1024))
+        truncate -s $imageSize $img
+
+        # Have to use GPT for the disk table, otherwise licheepi's u-boot will report:
+        #    ** Unrecognized filesystem type **
+        # 
+        # The "bootable" partition is where u-boot will look file for the bootloader
+        # information (dtbs, extlinux.conf file).
+        #
+        # Lichee Pi 4A will boot from its builtin spl flash first, so we don't need to
+        # set the bootable flag on the first partition.
+        sfdisk $img <<EOF
+            label: gpt
+            label-id: ${config.sdImage.firmwarePartitionID}
+            unit: sectors
+            sector-size: 512
+
+            start=''${gap}M, size=$firmwareSizeBlocks, type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, bootable
+            start=$((gap + ${toString config.sdImage.firmwareSize}))M, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4
+        EOF
+
+        # Copy the rootfs into the SD image
+        fsck.ext4 -vn $root_fs
+        eval $(partx $img -o START,SECTORS --nr 2 --pairs)
+        dd conv=notrunc if=$root_fs of=$img seek=$START count=$SECTORS
+
+        # Create a FAT32 /boot/firmware partition of suitable size into firmware_part.img
+        eval $(partx $img -o START,SECTORS --nr 1 --pairs)
+        truncate -s $((SECTORS * 512)) firmware_part.img
+
+        mkfs.vfat -i ${config.sdImage.firmwarePartitionID} -n ${config.sdImage.firmwarePartitionName} firmware_part.img
+
+        # Populate the files intended for /boot/firmware
+        mkdir firmware
+        ${config.sdImage.populateFirmwareCommands}
+
+        find firmware -exec touch --date=2000-01-01 {} +
+        # Copy the populated /boot/firmware into the SD image
+        cd firmware
+        # Force a fixed order in mcopy for better determinism, and avoid file globbing
+        for d in $(find . -type d -mindepth 1 | sort); do
+          faketime "2000-01-01 00:00:00" mmd -i ../firmware_part.img "::/$d"
+        done
+        for f in $(find . -type f | sort); do
+          mcopy -pvm -i ../firmware_part.img "$f" "::/$f"
+        done
+        cd ..
+
+        # Verify the FAT partition before copying it.
+        fsck.vfat -vn firmware_part.img
+        dd conv=notrunc if=firmware_part.img of=$img seek=$START count=$SECTORS
+
+        ${config.sdImage.postBuildCommands}
+
+        if test -n "$compressImage"; then
+            zstd -T$NIX_BUILD_CORES --rm $img
+        fi
+      '';
+    }) {};
+
+    boot.postBootCommands = lib.mkIf config.sdImage.expandOnBoot ''
+      # On the first boot do some maintenance tasks
+      if [ -f /nix-path-registration ]; then
+        set -euo pipefail
+        set -x
+        # Figure out device names for the boot device and root filesystem.
+        rootPart=$(${pkgs.util-linux}/bin/findmnt -n -o SOURCE /)
+        bootDevice=$(lsblk -npo PKNAME $rootPart)
+        partNum=$(lsblk -npo MAJ:MIN $rootPart | ${pkgs.gawk}/bin/awk -F: '{print $2}')
+
+        # Resize the root partition and the filesystem to fit the disk
+        echo ",+," | sfdisk -N$partNum --no-reread $bootDevice
+        ${pkgs.parted}/bin/partprobe
+        ${pkgs.e2fsprogs}/bin/resize2fs $rootPart
+
+        # Register the contents of the initial Nix store
+        ${config.nix.package.out}/bin/nix-store --load-db < /nix-path-registration
+
+        # nixos-rebuild also requires a "system" profile and an /etc/NIXOS tag.
+        touch /etc/NIXOS
+        ${config.nix.package.out}/bin/nix-env -p /nix/var/nix/profiles/system --set /run/current-system
+
+        # Prevents this from running on later boots.
+        rm -f /nix-path-registration
+      fi
+    '';
+  };
+}

nix/brain-kernel.nix

@@ -0,0 +1,21 @@
+{ pkgs }:
+let
+  src = builtins.path {
+    path = ../sources/linux-brain-brain;
+    name = "linux-brain";
+  };
+  version = "5.4.149";
+in pkgs.callPackage (pkgs.path + "/pkgs/os-specific/linux/kernel/generic.nix") {
+  # Match licheepi4a approach: use an older GCC stdenv for the kernel build.
+  # GCC 14 emits __aeabi_uldivmod for 64-bit divides in blk-iocost on ARMv5,
+  # and the kernel does not link libgcc. GCC 13 avoids this.
+  stdenv = pkgs.gcc13Stdenv;
+} {
+  inherit src version;
+  modDirVersion = version;
+  defconfig = "brain_defconfig";
+  kernelPatches = [];
+  extraMeta = {
+    description = "Linux kernel for SHARP Brain (i.MX28)";
+  };
+}

nix/brain-system.nix

@@ -0,0 +1,5 @@
+{ pkgs ? import ./pinned-nixpkgs.nix {} }:
+
+import (pkgs.path + "/nixos") {
+  configuration = ./sd-image-brain.nix;
+}

nix/overlays/llvm-tablegen.nix

@@ -0,0 +1,18 @@
+final: prev: let
+  lib = final.lib;
+  fixLLVM = pkg: let
+    stdenv = pkg.stdenv or final.stdenv;
+    isCross = stdenv.hostPlatform != stdenv.buildPlatform;
+  in pkg.overrideAttrs (old: if !isCross then {} else {
+    cmakeFlags = let
+      flags = old.cmakeFlags or [];
+      filtered = builtins.filter (f: !(lib.hasPrefix "-DLLVM_TABLEGEN=" f)) flags;
+      tblgen = "${final.buildPackages.llvmPackages_9.llvm}/bin/llvm-tblgen";
+    in filtered ++ [ "-DLLVM_TABLEGEN=${tblgen}" ];
+  });
+in {
+  llvmPackages_9 = prev.llvmPackages_9 // {
+    llvm = fixLLVM prev.llvmPackages_9.llvm;
+  };
+  llvm_9 = final.llvmPackages_9.llvm;
+}

nix/pinned-nixpkgs.nix

@@ -0,0 +1 @@
+import ../sources/nixpkgs

nix/platform.nix

@@ -0,0 +1,18 @@
+{ lib }:
+let
+  base = lib.systems.examples.sheevaplug;
+in base // {
+  system = "armv5tel-linux";
+
+  kernelAutoModules = true;
+  kernelBaseConfig = "brain_defconfig";
+  kernelTarget = "zImage";
+  kernelDTB = true;
+  kernelExtraConfig = ''
+    # Disable OABI for seccomp/systemd compatibility.
+    OABI_COMPAT n
+
+    # Onboard serial
+    SERIAL_OF_PLATFORM y
+  '';
+}

nix/sd-image-brain.nix

@@ -0,0 +1,79 @@
+{ config, lib, pkgs, modulesPath, ... }:
+
+let
+  extlinux-conf-builder =
+    import "${modulesPath}/system/boot/loader/generic-extlinux-compatible/extlinux-conf-builder.nix" {
+      pkgs = pkgs.buildPackages;
+    };
+  bootfiles = builtins.path {
+    path = ../bootfiles;
+    name = "brain-bootfiles";
+  };
+in
+{
+  imports = [
+    "${modulesPath}/profiles/base.nix"
+    "${modulesPath}/profiles/installation-device.nix"
+    "${modulesPath}/installer/cd-dvd/sd-image.nix"
+  ];
+
+  nixpkgs.crossSystem = import ./platform.nix { inherit lib; };
+  nixpkgs.overlays = [
+    (import ./overlays/llvm-tablegen.nix)
+  ];
+
+  boot.loader.grub.enable = false;
+  boot.loader.generic-extlinux-compatible.enable = true;
+
+  boot.kernelPackages = pkgs.linuxPackagesFor (import ./brain-kernel.nix { inherit pkgs; });
+  boot.kernelPatches = [];
+
+  hardware.deviceTree.enable = true;
+  hardware.firmware = lib.mkForce (
+    with pkgs; [
+      firmwareLinuxNonfree
+      intel2200BGFirmware
+      rtl8192su-firmware
+      rt5677-firmware
+      rtl8723bs-firmware
+      rtlwifi_new-firmware
+      zd1211fw
+      # alsa-firmware builds a host tool (tobin) that runs during build.
+      buildPackages.alsa-firmware
+      openelec-dvb-firmware
+    ]
+    ++ lib.optional (pkgs.stdenv.hostPlatform.isAarch32 || pkgs.stdenv.hostPlatform.isAarch64)
+      raspberrypiWirelessFirmware
+    ++ lib.optionals (lib.versionOlder config.boot.kernelPackages.kernel.version "4.13") [
+      rtl8723bs-firmware
+    ]
+  );
+
+  boot.kernelParams = [
+    "console=ttyAMA0,115200n8"
+    "console=tty1"
+    "rootwait"
+    "fbcon=font:ProFont6x11"
+  ];
+
+  networking.hostName = "brain";
+  networking.useDHCP = true;
+  services.openssh.enable = true;
+
+  system.stateVersion = "20.03";
+
+  sdImage = {
+    imageBaseName = "brain-nixos";
+    firmwareSize = 64;
+
+    populateFirmwareCommands = ''
+      # Copy Windows CE boot assets (BrainLILO, u-boot loader, etc.)
+      cp -R ${bootfiles}/. firmware/
+    '';
+
+    populateRootCommands = ''
+      mkdir -p ./files/boot
+      ${extlinux-conf-builder} -t 3 -c ${config.system.build.toplevel} -d ./files/boot
+    '';
+  };
+}

nix/uboot.nix

@@ -0,0 +1,36 @@
+{ pkgs ? import ./pinned-nixpkgs.nix {} }:
+
+let
+  pkgsCross = pkgs.pkgsCross.sheevaplug;
+  ubootPkgs = pkgsCross.callPackage (pkgs.path + "/pkgs/misc/uboot/default.nix") {};
+  buildUBoot = ubootPkgs.buildUBoot;
+  src = builtins.path {
+    path = ../sources/buildbrain/u-boot-brain;
+    name = "u-boot-brain";
+  };
+  patch = ../patches/u-boot-brain-extlinux.patch;
+  version = "2021.07-brain";
+
+  mk = defconfig: (buildUBoot {
+    inherit src defconfig version;
+    filesToInstall = [ "u-boot.bin" ];
+    extraConfig = "CONFIG_DISTRO_DEFAULTS=y\n";
+    extraPatches = [ patch ];
+    extraMeta = {
+      description = "U-Boot for SHARP Brain (i.MX28) with extlinux support";
+    };
+  }).overrideAttrs (_: {
+    patches = [ patch ];
+  });
+
+in {
+  pwsh1 = mk "pwsh1_defconfig";
+  pwsh2 = mk "pwsh2_defconfig";
+  pwsh3 = mk "pwsh3_defconfig";
+  pwsh4 = mk "pwsh4_defconfig";
+  pwsh5 = mk "pwsh5_defconfig";
+  pwsh6 = mk "pwsh6_defconfig";
+  pwsh7 = mk "pwsh7_defconfig";
+  pwa7200 = mk "pwa7200_defconfig";
+  pwa7400 = mk "pwa7400_defconfig";
+}

patches/kernel-arm926-asmtype.patch

@@ -0,0 +1,61 @@
+--- a/arch/arm/mm/proc-arm926.S
++++ b/arch/arm/mm/proc-arm926.S
+@@ -411,7 +411,7 @@
+ ENDPROC(cpu_arm926_do_resume)
+ #endif
+
+-	.type	__arm926_setup, #function
++	.type	__arm926_setup, %function
+ __arm926_setup:
+ 	mov	r0, #0
+ 	mcr	p15, 0, r0, c7, c7		@ invalidate I,D caches on v4
+@@ -443,7 +443,7 @@
+ 	 * .011 0001 ..11 0101
+ 	 * 
+ 	 */
+-	.type	arm926_crval, #object
++	.type	arm926_crval, %object
+ arm926_crval:
+ 	crval	clear=0x00007f3f, mmuset=0x00003135, ucset=0x00001134
+
+@@ -460,9 +460,9 @@
+
+ 	.align
+
+-	.section ".proc.info.init", #alloc
++	.section ".proc.info.init", "a"
+
+-	.type	__arm926_proc_info,#object
++	.type	__arm926_proc_info,%object
+ __arm926_proc_info:
+ 	.long	0x41069260			@ ARM926EJ-S (v5TEJ)
+ 	.long	0xff0ffff0
+--- a/arch/arm/mm/proc-macros.S
++++ b/arch/arm/mm/proc-macros.S
+@@ -282,7 +282,7 @@
+ #if defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
+ 	.section ".rodata"
+ #endif
+-	.type	\name\()_processor_functions, #object
++	.type	\name\()_processor_functions, %object
+ 	.align 2
+ ENTRY(\name\()_processor_functions)
+ 	.word	\dabort
+@@ -324,7 +324,7 @@
+
+ .macro define_cache_functions name:req
+ 	.align 2
+-	.type	\name\()_cache_fns, #object
++	.type	\name\()_cache_fns, %object
+ ENTRY(\name\()_cache_fns)
+ 	.long	\name\()_flush_icache_all
+ 	.long	\name\()_flush_kern_cache_all
+@@ -341,7 +341,7 @@
+ .endm
+
+ .macro define_tlb_functions name:req, flags_up:req, flags_smp
+-	.type	\name\()_tlb_fns, #object
++	.type	\name\()_tlb_fns, %object
+ ENTRY(\name\()_tlb_fns)
+ 	.long	\name\()_flush_user_tlb_range
+ 	.long	\name\()_flush_kern_tlb_range

patches/u-boot-brain-extlinux.patch

@@ -0,0 +1,51 @@
+--- a/include/configs/brain_mx28_common.h
++++ b/include/configs/brain_mx28_common.h
+@@ -52,6 +52,15 @@
+ #define CONFIG_LOADADDR		0x42000000
+ #define CONFIG_SYS_LOAD_ADDR	CONFIG_LOADADDR
+ 
++
++#define BOOT_TARGET_DEVICES(func) \
++	func(MMC, mmc, 1) \
++	func(MMC, mmc, 0)
++
++#define CONFIG_BOOTCOMMAND "run distro_bootcmd; run bootcmd_legacy"
++
++#include <config_distro_bootcmd.h>
++
+ /* Extra Environment */
+ #define CONFIG_EXTRA_ENV_SETTINGS \
+ 	"stdin=serial\0" \
+@@ -60,9 +69,15 @@
+ 	"bootdelay=0\0" \
+ 	"videomode=video=ctfb:x:" CONFIG_LCD_X ",y:" CONFIG_LCD_Y ",depth:16,pclk:30857,le:0,ri:0,up:0,lo:0,hs:0,vs:0,sync:0,vmode:0\0" \
+ 	"image=zImage\0" \
++	"kernel_addr_r=0x42000000\0" \
++	"fdt_addr_r=0x41000000\0" \
++	"ramdisk_addr_r=0x43000000\0" \
++	"scriptaddr=0x40800000\0" \
++	"pxefile_addr_r=0x40800000\0" \
+ 	"console_mainline=ttyAMA0\0" \
+ 	"bootargs_custom=fbcon=font:ProFont6x11\0" \
+ 	"bootorder=emmc sd\0" \
++	"fdtfile=" CONFIG_DEFAULT_FDT_FILE "\0" \
+ 	"fdt_file=" CONFIG_DEFAULT_FDT_FILE "\0" \
+ 	"fdt_addr=0x41000000\0" \
+ 	"verbose=no\0" \
+@@ -147,13 +162,14 @@
+ 				"run loadandimportenv; " \
+ 			"fi; " \
+ 		"done\0" \
+-	"bootcmd=" \
++	"bootcmd_legacy=" \
+ 		"for choice in $bootorder; do " \
+ 			"if run select$choice; then " \
+ 				"run mmcboot; " \
+ 			"fi; " \
+ 		"done; " \
+-		"echo Failed to boot (X_X)"
++		"echo Failed to boot (X_X)\0" \
++	BOOTENV
+ 
+ /* The rest of the configuration is shared */
+ #include <configs/mxs.h>

sources/buildbrain

@@ -0,0 +1 @@
+Subproject commit cf7cc41efe532ab27bd8bf02ba85145fa2b29c81

sources/linux-brain-brain

@@ -0,0 +1 @@
+Subproject commit 72ae0eb2be8ed5d4e547f2183b6d4a66d6fb9f33

sources/nixos-licheepi4a

@@ -0,0 +1 @@
+Subproject commit 0fb4b65137de445de543ed8532d4aac6ecc27271

sources/nixpkgs/.editorconfig

@@ -0,0 +1,28 @@
+# EditorConfig configuration for nixpkgs
+# http://EditorConfig.org
+
+# Top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file, utf-8 charset
+[*]
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+charset = utf-8
+
+# see https://nixos.org/nixpkgs/manual/#chap-conventions
+
+# Match nix/ruby/docbook files, set indent to spaces with width of two
+[*.{nix,rb,xml}]
+indent_style = space
+indent_size = 2
+
+# Match shell/python/perl scripts, set indent to spaces with width of four
+[*.{sh,py,pl}]
+indent_style = space
+indent_size = 4
+
+# Match diffs, avoid to trim trailing whitespace
+[*.{diff,patch}]
+trim_trailing_whitespace = false

sources/nixpkgs/.gitattributes

@@ -0,0 +1,16 @@
+**/deps.nix linguist-generated
+**/node-packages.nix linguist-generated
+
+pkgs/applications/editors/emacs-modes/*-generated.nix linguist-generated
+pkgs/development/r-modules/*-packages.nix linguist-generated
+pkgs/development/haskell-modules/hackage-packages.nix linguist-generated
+pkgs/development/beam-modules/hex-packages.nix linguist-generated
+
+doc/** linguist-documentation
+doc/default.nix linguist-documentation=false
+
+nixos/doc/** linguist-documentation
+nixos/doc/default.nix linguist-documentation=false
+
+nixos/modules/module-list.nix merge=union
+# pkgs/top-level/all-packages.nix merge=union

sources/nixpkgs/.github/CODEOWNERS

@@ -0,0 +1,177 @@
+# CODEOWNERS file
+#
+# This file is used to describe who owns what in this repository. This file does not
+# replace `meta.maintainers` but is instead used for other things than derivations
+# and modules, like documentation, package sets, and other assets.
+#
+# For documentation on this file, see https://help.github.com/articles/about-codeowners/
+# Mentioned users will get code review requests.
+
+# This file
+/.github/CODEOWNERS @edolstra
+
+# Libraries
+/lib                        @edolstra @nbp
+/lib/systems                @nbp @ericson2314 @matthewbauer
+/lib/generators.nix         @edolstra @nbp @Profpatsch
+/lib/debug.nix              @edolstra @nbp @Profpatsch
+
+# Nixpkgs Internals
+/default.nix                          @nbp
+/pkgs/top-level/default.nix           @nbp @Ericson2314
+/pkgs/top-level/impure.nix            @nbp @Ericson2314
+/pkgs/top-level/stage.nix             @nbp @Ericson2314 @matthewbauer
+/pkgs/top-level/splice.nix            @Ericson2314 @matthewbauer
+/pkgs/top-level/release-cross.nix     @Ericson2314 @matthewbauer
+/pkgs/stdenv/generic                  @Ericson2314 @matthewbauer
+/pkgs/stdenv/cross                    @Ericson2314 @matthewbauer
+/pkgs/build-support/cc-wrapper        @Ericson2314 @orivej
+/pkgs/build-support/bintools-wrapper  @Ericson2314 @orivej
+/pkgs/build-support/setup-hooks       @Ericson2314
+
+# NixOS Internals
+/nixos/default.nix          @nbp
+/nixos/lib/from-env.nix     @nbp
+/nixos/lib/eval-config.nix  @nbp
+/nixos/doc/manual/configuration/abstractions.xml      @nbp
+/nixos/doc/manual/configuration/config-file.xml       @nbp
+/nixos/doc/manual/configuration/config-syntax.xml     @nbp
+/nixos/doc/manual/configuration/modularity.xml        @nbp
+/nixos/doc/manual/development/assertions.xml          @nbp
+/nixos/doc/manual/development/meta-attributes.xml     @nbp
+/nixos/doc/manual/development/option-declarations.xml @nbp
+/nixos/doc/manual/development/option-def.xml          @nbp
+/nixos/doc/manual/development/option-types.xml        @nbp
+/nixos/doc/manual/development/replace-modules.xml     @nbp
+/nixos/doc/manual/development/writing-modules.xml     @nbp
+/nixos/doc/manual/man-nixos-option.xml                @nbp
+/nixos/modules/installer/tools/nixos-option.sh        @nbp
+
+# NixOS integration test driver
+/nixos/lib/test-driver  @tfc
+
+# New NixOS modules
+/nixos/modules/module-list.nix @Infinisil
+
+# Python-related code and docs
+/maintainers/scripts/update-python-libraries	@FRidh
+/pkgs/top-level/python-packages.nix     @FRidh @jonringer
+/pkgs/development/interpreters/python   @FRidh
+/pkgs/development/python-modules        @FRidh @jonringer
+/doc/languages-frameworks/python.section.md     @FRidh
+
+# Haskell
+/pkgs/development/compilers/ghc                       @basvandijk @cdepillabout
+/pkgs/development/haskell-modules                     @basvandijk @cdepillabout
+/pkgs/development/haskell-modules/default.nix         @basvandijk @cdepillabout
+/pkgs/development/haskell-modules/generic-builder.nix @basvandijk @cdepillabout
+/pkgs/development/haskell-modules/hoogle.nix          @basvandijk @cdepillabout
+
+# Perl
+/pkgs/development/interpreters/perl @volth
+/pkgs/top-level/perl-packages.nix   @volth
+/pkgs/development/perl-modules      @volth
+
+# R
+/pkgs/applications/science/math/R   @peti
+/pkgs/development/r-modules         @peti
+
+# Ruby
+/pkgs/development/interpreters/ruby @alyssais @zimbatm
+/pkgs/development/ruby-modules      @alyssais @zimbatm
+
+# Rust
+/pkgs/development/compilers/rust @Mic92 @LnL7
+
+# Darwin-related
+/pkgs/stdenv/darwin         @NixOS/darwin-maintainers
+/pkgs/os-specific/darwin    @NixOS/darwin-maintainers
+
+# C compilers
+/pkgs/development/compilers/gcc @matthewbauer
+/pkgs/development/compilers/llvm @matthewbauer
+
+# Compatibility stuff
+/pkgs/top-level/unix-tools.nix @matthewbauer
+/pkgs/development/tools/xcbuild @matthewbauer
+
+# Beam-related (Erlang, Elixir, LFE, etc)
+/pkgs/development/beam-modules                  @gleber
+/pkgs/development/interpreters/erlang           @gleber
+/pkgs/development/interpreters/lfe              @gleber
+/pkgs/development/interpreters/elixir           @gleber
+/pkgs/development/tools/build-managers/rebar    @gleber
+/pkgs/development/tools/build-managers/rebar3   @gleber
+/pkgs/development/tools/erlang                  @gleber
+
+# Jetbrains
+/pkgs/applications/editors/jetbrains @edwtjo
+
+# Eclipse
+/pkgs/applications/editors/eclipse @rycee
+
+# Licenses
+/lib/licenses.nix @alyssais
+
+# Qt / KDE
+/pkgs/applications/kde @ttuegel
+/pkgs/desktops/plasma-5 @ttuegel
+/pkgs/development/libraries/kde-frameworks @ttuegel
+/pkgs/development/libraries/qt-5 @ttuegel
+
+# PostgreSQL and related stuff
+/pkgs/servers/sql/postgresql @thoughtpolice
+/nixos/modules/services/databases/postgresql.xml @thoughtpolice
+/nixos/modules/services/databases/postgresql.nix @thoughtpolice
+/nixos/tests/postgresql.nix @thoughtpolice
+
+# Hardened profile & related modules
+/nixos/modules/profiles/hardened.nix @joachifm
+/nixos/modules/security/hidepid.nix @joachifm
+/nixos/modules/security/lock-kernel-modules.nix @joachifm
+/nixos/modules/security/misc.nix @joachifm
+/nixos/tests/hardened.nix @joachifm
+/pkgs/os-specific/linux/kernel/hardened-config.nix @joachifm
+
+# Network Time Daemons
+/pkgs/tools/networking/chrony @thoughtpolice
+/pkgs/tools/networking/ntp @thoughtpolice
+/pkgs/tools/networking/openntpd @thoughtpolice
+/nixos/modules/services/networking/ntp @thoughtpolice
+
+# Dhall
+/pkgs/development/dhall-modules      @Gabriel439 @Profpatsch
+/pkgs/development/interpreters/dhall @Gabriel439 @Profpatsch
+
+# Idris
+/pkgs/development/idris-modules @Infinisil
+
+# Bazel
+/pkgs/development/tools/build-managers/bazel @mboes @Profpatsch
+
+# NixOS modules for e-mail and dns services
+/nixos/modules/services/mail/mailman.nix    @peti
+/nixos/modules/services/mail/postfix.nix    @peti
+/nixos/modules/services/networking/bind.nix @peti
+/nixos/modules/services/mail/rspamd.nix     @peti
+
+# Emacs
+/pkgs/applications/editors/emacs-modes @adisbladis
+/pkgs/applications/editors/emacs       @adisbladis
+/pkgs/top-level/emacs-packages.nix     @adisbladis
+
+# VimPlugins
+/pkgs/misc/vim-plugins         @jonringer
+
+# VsCode Extensions
+/pkgs/misc/vscode-extensions   @jonringer
+
+# Prometheus exporter modules and tests
+/nixos/modules/services/monitoring/prometheus/exporters.nix  @WilliButz
+/nixos/modules/services/monitoring/prometheus/exporters.xml  @WilliButz
+/nixos/tests/prometheus-exporters.nix                        @WilliButz
+
+# PHP
+/pkgs/development/interpreters/php  @etu
+/pkgs/top-level/php-packages.nix    @etu
+/pkgs/build-support/build-pecl.nix  @etu

sources/nixpkgs/.github/CONTRIBUTING.md

@@ -0,0 +1,53 @@
+# How to contribute
+
+Note: contributing implies licensing those contributions
+under the terms of [COPYING](../COPYING), which is an MIT-like license.
+
+## Opening issues
+
+* Make sure you have a [GitHub account](https://github.com/signup/free)
+* Make sure there is no open issue on the topic
+* [Submit a new issue](https://github.com/NixOS/nixpkgs/issues/new/choose) by choosing the kind of topic and fill out the template
+
+## Submitting changes
+
+* Format the commit messages in the following way:
+
+  ```
+  (pkg-name | nixos/<module>): (from -> to | init at version | refactor | etc)
+
+  (Motivation for change. Additional information.)
+  ```
+
+  For consistency, there should not be a period at the end of the commit message's summary line (the first line of the commit message).
+
+  Examples:
+
+  * nginx: init at 2.0.1
+  * firefox: 54.0.1 -> 55.0
+  * nixos/hydra: add bazBaz option
+
+    Dual baz behavior is needed to do foo.
+  * nixos/nginx: refactor config generation
+
+    The old config generation system used impure shell scripts and could break in specific circumstances (see #1234).
+
+* `meta.description` should:
+  * Be capitalized.
+  * Not start with the package name.
+  * Not have a period at the end.
+* `meta.license` must be set and fit the upstream license.
+  * If there is no upstream license, `meta.license` should default to `stdenv.lib.licenses.unfree`.
+* `meta.maintainers` must be set.
+
+See the nixpkgs manual for more details on [standard meta-attributes](https://nixos.org/nixpkgs/manual/#sec-standard-meta-attributes) and on how to [submit changes to nixpkgs](https://nixos.org/nixpkgs/manual/#chap-submitting-changes).
+
+## Writing good commit messages
+
+In addition to writing properly formatted commit messages, it's important to include relevant information so other developers can later understand *why* a change was made. While this information usually can be found by digging code, mailing list/Discourse archives, pull request discussions or upstream changes, it may require a lot of work.
+
+For package version upgrades and such a one-line commit message is usually sufficient.
+
+## Reviewing contributions
+
+See the nixpkgs manual for more details on how to [Review contributions](https://nixos.org/nixpkgs/manual/#chap-reviewing-contributions).

sources/nixpkgs/.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,11 @@
+## Issue description
+
+
+
+### Steps to reproduce
+
+
+
+## Technical details
+
+Please run `nix run nixpkgs.nix-info -c nix-info -m` and paste the result.

sources/nixpkgs/.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,37 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: '0.kind: bug'
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. ...
+2. ...
+3. ...
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Additional context**
+Add any other context about the problem here.
+
+**Metadata**
+Please run `nix run nixpkgs.nix-info -c nix-info -m` and paste the result.
+
+Maintainer information:
+```yaml
+# a list of nixpkgs attributes affected by the problem
+attribute:
+# a list of nixos modules affected by the problem
+module:
+```

sources/nixpkgs/.github/ISSUE_TEMPLATE/packaging_request.md

@@ -0,0 +1,18 @@
+---
+name: Packaging requests
+about: For packages that are missing
+title: ''
+labels: '0.kind: packaging request'
+assignees: ''
+
+---
+
+**Project description**
+_describe the project a little_
+
+**Metadata**
+
+* homepage URL:
+* source URL:
+* license: mit, bsd, gpl2+ , ...
+* platforms: unix, linux, darwin, ...

sources/nixpkgs/.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,23 @@
+<!-- Nixpkgs has a lot of new incoming Pull Requests, but not enough people to review this constant stream. Even if you aren't a committer, we would appreciate reviews of other PRs, especially simple ones like package updates. Just testing the relevant package/service and leaving a comment saying what you tested, how you tested it and whether it worked would be great. List of open PRs: <https://github.com/NixOS/nixpkgs/pulls>, for more about reviewing contributions: <https://hydra.nixos.org/job/nixpkgs/trunk/manual/latest/download/1/nixpkgs/manual.html#chap-reviewing-contributions>. Reviewing isn't mandatory, but it would help out a lot and reduce the average time-to-merge for all of us. Thanks a lot if you do! -->
+###### Motivation for this change
+
+
+###### Things done
+
+<!-- Please check what applies. Note that these are not hard requirements but merely serve as information for reviewers. -->
+
+- [ ] Tested using sandboxing ([nix.useSandbox](http://nixos.org/nixos/manual/options.html#opt-nix.useSandbox) on NixOS, or option `sandbox` in [`nix.conf`](http://nixos.org/nix/manual/#sec-conf-file) on non-NixOS linux)
+- Built on platform(s)
+   - [ ] NixOS
+   - [ ] macOS
+   - [ ] other Linux distributions
+- [ ] Tested via one or more NixOS test(s) if existing and applicable for the change (look inside [nixos/tests](https://github.com/NixOS/nixpkgs/blob/master/nixos/tests))
+- [ ] Tested compilation of all pkgs that depend on this change using `nix-shell -p nixpkgs-review --run "nixpkgs-review wip"`
+- [ ] Tested execution of all binary files (usually in `./result/bin/`)
+- [ ] Determined the impact on package closure size (by running `nix path-info -S` before and after)
+- [ ] Ensured that relevant documentation is up to date
+- [ ] Fits [CONTRIBUTING.md](https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md).
+
+###### Notify maintainers
+
+cc @

sources/nixpkgs/.github/stale.yml

@@ -0,0 +1,32 @@
+# Number of days of inactivity before an issue becomes stale
+daysUntilStale: 180
+# Number of days of inactivity before a stale issue is closed
+daysUntilClose: false
+# Issues with these labels will never be considered stale
+exemptLabels:
+  - 1.severity: security
+# Label to use when marking an issue as stale
+staleLabel: 2.status: stale
+# Comment to post when marking an issue as stale. Set to `false` to disable
+markComment: >
+  Thank you for your contributions.
+
+  This has been automatically marked as stale because it has had no
+  activity for 180 days.
+
+  If this is still important to you, we ask that you leave a
+  comment below. Your comment can be as simple as "still important
+  to me". This lets people see that at least one person still cares
+  about this. Someone will have to do this at most twice a year if
+  there is no other activity.
+
+  Here are suggestions that might help resolve this more quickly:
+
+  1. Search for maintainers and people that previously touched the
+     related code and @ mention them in a comment.
+  2. Ask on the [NixOS Discourse](https://discourse.nixos.org/).
+  3. Ask on the [#nixos channel](irc://irc.freenode.net/#nixos) on
+     [irc.freenode.net](https://freenode.net).
+
+# Comment to post when closing a stale issue. Set to `false` to disable
+closeComment: false

sources/nixpkgs/.gitignore

@@ -0,0 +1,17 @@
+*~
+,*
+.*.swp
+.*.swo
+result
+result-*
+/doc/NEWS.html
+/doc/NEWS.txt
+/doc/manual.html
+/doc/manual.pdf
+.version-suffix
+
+.DS_Store
+
+/pkgs/development/libraries/qt-5/*/tmp/
+/pkgs/desktops/kde-5/*/tmp/
+/pkgs/development/mobile/androidenv/xml/*

sources/nixpkgs/.version

@@ -0,0 +1 @@
+20.03

sources/nixpkgs/COPYING

@@ -0,0 +1,20 @@
+Copyright (c) 2003-2019 Eelco Dolstra and the Nixpkgs/NixOS contributors
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

sources/nixpkgs/README.md

@@ -0,0 +1,111 @@
+<p align="center">
+  <a href="https://nixos.org/nixos"><img src="https://nixos.org/logo/nixos-hires.png" width="500px" alt="NixOS logo" /></a>
+</p>
+
+<p align="center">
+  <a href="https://www.codetriage.com/nixos/nixpkgs"><img src="https://www.codetriage.com/nixos/nixpkgs/badges/users.svg" alt="Code Triagers badge" /></a>
+  <a href="https://opencollective.com/nixos"><img src="https://opencollective.com/nixos/tiers/supporter/badge.svg?label=Supporter&color=brightgreen" alt="Open Collective supporters" /></a>
+</p>
+
+[Nixpkgs](https://github.com/nixos/nixpkgs) is a collection of over
+40,000 software packages that can be installed with the
+[Nix](https://nixos.org/nix/) package manager. It also implements
+[NixOS](https://nixos.org/nixos/), a purely-functional Linux distribution.
+
+# Manuals
+
+* [NixOS Manual](https://nixos.org/nixos/manual) - how to install, configure, and maintain a purely-functional Linux distribution
+* [Nixpkgs Manual](https://nixos.org/nixpkgs/manual/) - contributing to Nixpkgs and using programming-language-specific Nix expressions
+* [Nix Package Manager Manual](https://nixos.org/nix/manual) - how to write Nix expresssions (programs), and how to use Nix command line tools
+
+# Community
+
+* [Discourse Forum](https://discourse.nixos.org/)
+* [IRC - #nixos on freenode.net](irc://irc.freenode.net/#nixos)
+* [NixOS Weekly](https://weekly.nixos.org/)
+* [Community-maintained wiki](https://nixos.wiki/)
+
+# Other Project Repositories
+
+The sources of all offical Nix-related projects are in the [NixOS
+organization on GitHub](https://github.com/NixOS/). Here are some of
+the main ones:
+
+* [Nix](https://github.com/NixOS/nix) - the purely functional package manager
+* [NixOps](https://github.com/NixOS/nixops) - the tool to remotely deploy NixOS machines
+* [Nix RFCs](https://github.com/NixOS/rfcs) - the formal process for making substantial changes to the community
+* [NixOS homepage](https://github.com/NixOS/nixos-homepage) - the [NixOS.org](https://nixos.org) website
+* [hydra](https://github.com/NixOS/hydra) - our continuous integration system
+* [NixOS Artwork](https://github.com/NixOS/nixos-artwork) - NixOS artwork
+
+# Continuous Integration and Distribution
+
+Nixpkgs and NixOS are built and tested by our continuous integration
+system, [Hydra](https://hydra.nixos.org/).
+
+* [Continuous package builds for unstable/master](https://hydra.nixos.org/jobset/nixos/trunk-combined)
+* [Continuous package builds for the NixOS 19.09 release](https://hydra.nixos.org/jobset/nixos/release-19.09)
+* [Tests for unstable/master](https://hydra.nixos.org/job/nixos/trunk-combined/tested#tabs-constituents)
+* [Tests for the NixOS 19.09 release](https://hydra.nixos.org/job/nixos/release-19.09/tested#tabs-constituents)
+
+Artifacts successfully built with Hydra are published to cache at
+https://cache.nixos.org/. When successful build and test criteria are
+met, the Nixpkgs expressions are distributed via [Nix
+channels](https://nixos.org/nix/manual/#sec-channels).
+
+# Contributing
+
+Nixpkgs is among the most active projects on GitHub. While thousands
+of open issues and pull requests might seem a lot at first, it helps
+consider it in the context of the scope of the project. Nixpkgs
+describes how to build over 40,000 pieces of software and implements a
+Linux distribution. The [GitHub Insights](https://github.com/NixOS/nixpkgs/pulse)
+page gives a sense of the project activity.
+
+Community contributions are always welcome through GitHub Issues and
+Pull Requests. When pull requests are made, our tooling automation bot,
+[OfBorg](https://github.com/NixOS/ofborg) will perform various checks
+to help ensure expression quality.
+
+The *Nixpkgs maintainers* are people who have assigned themselves to
+maintain specific individual packages. We encourage people who care
+about a package to assign themselves as a maintainer. When a pull
+request is made against a package, OfBorg will notify the appropriate
+maintainer(s). The *Nixpkgs committers* are people who have been given
+permission to merge.
+
+Most contributions are based on and merged into these branches:
+
+* `master` is the main branch where all small contributions go
+* `staging` is branched from master, changes that have a big impact on
+  Hydra builds go to this branch
+* `staging-next` is branched from staging and only fixes to stabilize
+  and security fixes with a big impact on Hydra builds should be
+  contributed to this branch. This branch is merged into master when
+  deemed of sufficiently high quality
+
+For more information about contributing to the project, please visit
+the [contributing page](https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md).
+
+# Donations
+
+The infrastructure for NixOS and related projects is maintained by a
+nonprofit organization, the [NixOS
+Foundation](https://nixos.org/nixos/foundation.html). To ensure the
+continuity and expansion of the NixOS infrastructure, we are looking
+for donations to our organization.
+
+You can donate to the NixOS foundation by using Open Collective:
+
+<a href="https://opencollective.com/nixos#support"><img src="https://opencollective.com/nixos/tiers/supporter.svg?width=890" /></a>
+
+# License
+
+Nixpkgs is licensed under the [MIT License](COPYING).
+
+Note: MIT license does not apply to the packages built by Nixpkgs,
+merely to the files in this repository (the Nix expressions, build
+scripts, NixOS modules, etc.). It also might not apply to patches
+included in Nixpkgs, which may be derivative works of the packages to
+which they apply. The aforementioned artifacts are all covered by the
+licenses of the respective packages.

sources/nixpkgs/default.nix

@@ -0,0 +1,28 @@
+let requiredVersion = import ./lib/minver.nix; in
+
+if ! builtins ? nixVersion || builtins.compareVersions requiredVersion builtins.nixVersion == 1 then
+
+  abort ''
+
+    This version of Nixpkgs requires Nix >= ${requiredVersion}, please upgrade:
+
+    - If you are running NixOS, `nixos-rebuild' can be used to upgrade your system.
+
+    - Alternatively, with Nix > 2.0 `nix upgrade-nix' can be used to imperatively
+      upgrade Nix. You may use `nix-env --version' to check which version you have.
+
+    - If you installed Nix using the install script (https://nixos.org/nix/install),
+      it is safe to upgrade by running it again:
+
+          curl https://nixos.org/nix/install | sh
+
+    For more information, please see the NixOS release notes at
+    https://nixos.org/nixos/manual or locally at
+    ${toString ./nixos/doc/manual/release-notes}.
+
+    If you need further help, see https://nixos.org/nixos/support.html
+  ''
+
+else
+
+  import ./pkgs/top-level/impure.nix

sources/nixpkgs/doc/.gitignore

@@ -0,0 +1,8 @@
+*.chapter.xml
+*.section.xml
+.version
+functions/library/generated
+functions/library/locations.xml
+highlightjs
+manual-full.xml
+out

sources/nixpkgs/doc/Makefile

@@ -0,0 +1,110 @@
+MD_TARGETS=$(addsuffix .xml, $(basename $(wildcard ./*.md ./**/*.md)))
+
+.PHONY: all
+all: validate format out/html/index.html out/epub/manual.epub
+
+.PHONY: debug
+debug:
+	nix-shell --run "xmloscopy --docbook5 ./manual.xml ./manual-full.xml"
+
+.PHONY: format
+format: doc-support/result
+	find . -iname '*.xml' -type f | while read f; do \
+		echo $$f ;\
+		xmlformat --config-file "doc-support/result/xmlformat.conf" -i $$f ;\
+	done
+
+.PHONY: fix-misc-xml
+fix-misc-xml:
+	find . -iname '*.xml' -type f \
+		-exec ../nixos/doc/varlistentry-fixer.rb {} ';'
+
+.PHONY: clean
+clean:
+	rm -f ${MD_TARGETS} doc-support/result .version manual-full.xml functions/library/locations.xml functions/library/generated
+	rm -rf ./out/ ./highlightjs
+
+.PHONY: validate
+validate: manual-full.xml doc-support/result
+	jing doc-support/result/docbook.rng manual-full.xml
+
+out/html/index.html: doc-support/result manual-full.xml style.css highlightjs
+	mkdir -p out/html
+	xsltproc \
+		--nonet --xinclude \
+		--output $@ \
+		doc-support/result/xhtml.xsl \
+		./manual-full.xml
+
+	mkdir -p out/html/highlightjs/
+	cp -r highlightjs out/html/
+
+	cp ./overrides.css out/html/
+	cp ./style.css out/html/style.css
+
+	mkdir -p out/html/images/callouts
+	cp doc-support/result/xsl/docbook/images/callouts/*.svg out/html/images/callouts/
+	chmod u+w -R out/html/
+
+out/epub/manual.epub: manual-full.xml
+	mkdir -p out/epub/scratch
+	xsltproc --nonet \
+		--output out/epub/scratch/ \
+		doc-support/result/epub.xsl \
+		./manual-full.xml
+
+	cp ./overrides.css out/epub/scratch/OEBPS
+	cp ./style.css out/epub/scratch/OEBPS
+	mkdir -p out/epub/scratch/OEBPS/images/callouts/
+	cp doc-support/result/xsl/docbook/images/callouts/*.svg out/epub/scratch/OEBPS/images/callouts/
+	echo "application/epub+zip" > mimetype
+	zip -0Xq "out/epub/manual.epub" mimetype
+	rm mimetype
+	cd "out/epub/scratch/" && zip -Xr9D "../manual.epub" *
+	rm -rf "out/epub/scratch/"
+
+highlightjs: doc-support/result
+	mkdir -p highlightjs
+	cp -r doc-support/result/highlightjs/highlight.pack.js highlightjs/
+	cp -r doc-support/result/highlightjs/LICENSE highlightjs/
+	cp -r doc-support/result/highlightjs/mono-blue.css highlightjs/
+	cp -r doc-support/result/highlightjs/loader.js highlightjs/
+
+
+manual-full.xml: ${MD_TARGETS} .version functions/library/locations.xml functions/library/generated *.xml **/*.xml **/**/*.xml
+	xmllint --nonet --xinclude --noxincludenode manual.xml --output manual-full.xml
+
+.version: doc-support/result
+	ln -rfs ./doc-support/result/version .version
+
+doc-support/result: doc-support/default.nix
+	(cd doc-support; nix-build)
+
+functions/library/locations.xml: doc-support/result
+	ln -rfs ./doc-support/result/function-locations.xml functions/library/locations.xml
+
+functions/library/generated: doc-support/result
+	ln -rfs ./doc-support/result/function-docs functions/library/generated
+
+%.section.xml: %.section.md
+	pandoc $^ -w docbook+smart \
+		-f markdown+smart \
+	  | sed -e 's|<ulink url=|<link xlink:href=|' \
+	      -e 's|</ulink>|</link>|' \
+	      -e 's|<sect. id=|<section xml:id=|' \
+	      -e 's|</sect[0-9]>|</section>|' \
+	      -e '1s| id=| xml:id=|' \
+	      -e '1s|\(<[^ ]* \)|\1xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" |' \
+	| cat  > $@
+
+%.chapter.xml: %.chapter.md
+	pandoc $^ -w docbook+smart \
+		--top-level-division=chapter \
+		-f markdown+smart \
+	  | sed -e 's|<ulink url=|<link xlink:href=|' \
+	      -e 's|</ulink>|</link>|' \
+	      -e 's|<sect. id=|<section xml:id=|' \
+	      -e 's|</sect[0-9]>|</section>|' \
+	      -e '1s| id=| xml:id=|' \
+	      -e '1s|\(<[^ ]* \)|\1|' \
+	| cat  > $@

sources/nixpkgs/doc/builders/fetchers.xml

@@ -0,0 +1,150 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="chap-pkgs-fetchers">
+ <title>Fetchers</title>
+ <para>
+  When using Nix, you will frequently need to download source code and other files from the internet. Nixpkgs comes with a few helper functions that allow you to fetch fixed-output derivations in a structured way.
+ </para>
+ <para>
+  The two fetcher primitives are <function>fetchurl</function> and <function>fetchzip</function>. Both of these have two required arguments, a URL and a hash. The hash is typically <literal>sha256</literal>, although many more hash algorithms are supported. Nixpkgs contributors are currently recommended to use <literal>sha256</literal>. This hash will be used by Nix to identify your source. A typical usage of fetchurl is provided below.
+ </para>
+<programlisting><![CDATA[
+{ stdenv, fetchurl }:
+
+stdenv.mkDerivation {
+  name = "hello";
+  src = fetchurl {
+    url = "http://www.example.org/hello.tar.gz";
+    sha256 = "1111111111111111111111111111111111111111111111111111";
+  };
+}
+]]></programlisting>
+ <para>
+  The main difference between <function>fetchurl</function> and <function>fetchzip</function> is in how they store the contents. <function>fetchurl</function> will store the unaltered contents of the URL within the Nix store. <function>fetchzip</function> on the other hand will decompress the archive for you, making files and directories directly accessible in the future. <function>fetchzip</function> can only be used with archives. Despite the name, <function>fetchzip</function> is not limited to .zip files and can also be used with any tarball.
+ </para>
+ <para>
+  <function>fetchpatch</function> works very similarly to <function>fetchurl</function> with the same arguments expected. It expects patch files as a source and and performs normalization on them before computing the checksum. For example it will remove comments or other unstable parts that are sometimes added by version control systems and can change over time.
+ </para>
+ <para>
+  Other fetcher functions allow you to add source code directly from a VCS such as subversion or git. These are mostly straightforward names based on the name of the command used with the VCS system. Because they give you a working repository, they act most like <function>fetchzip</function>.
+ </para>
+ <variablelist>
+  <varlistentry>
+   <term>
+    <literal>fetchsvn</literal>
+   </term>
+   <listitem>
+    <para>
+     Used with Subversion. Expects <literal>url</literal> to a Subversion directory, <literal>rev</literal>, and <literal>sha256</literal>.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>fetchgit</literal>
+   </term>
+   <listitem>
+    <para>
+     Used with Git. Expects <literal>url</literal> to a Git repo, <literal>rev</literal>, and <literal>sha256</literal>. <literal>rev</literal> in this case can be full the git commit id (SHA1 hash) or a tag name like <literal>refs/tags/v1.0</literal>.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>fetchfossil</literal>
+   </term>
+   <listitem>
+    <para>
+     Used with Fossil. Expects <literal>url</literal> to a Fossil archive, <literal>rev</literal>, and <literal>sha256</literal>.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>fetchcvs</literal>
+   </term>
+   <listitem>
+    <para>
+     Used with CVS. Expects <literal>cvsRoot</literal>, <literal>tag</literal>, and <literal>sha256</literal>.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>fetchhg</literal>
+   </term>
+   <listitem>
+    <para>
+     Used with Mercurial. Expects <literal>url</literal>, <literal>rev</literal>, and <literal>sha256</literal>.
+    </para>
+   </listitem>
+  </varlistentry>
+ </variablelist>
+ <para>
+  A number of fetcher functions wrap part of <function>fetchurl</function> and <function>fetchzip</function>. They are mainly convenience functions intended for commonly used destinations of source code in Nixpkgs. These wrapper fetchers are listed below.
+ </para>
+ <variablelist>
+  <varlistentry>
+   <term>
+    <literal>fetchFromGitHub</literal>
+   </term>
+   <listitem>
+    <para>
+     <function>fetchFromGitHub</function> expects four arguments. <literal>owner</literal> is a string corresponding to the GitHub user or organization that controls this repository. <literal>repo</literal> corresponds to the name of the software repository. These are located at the top of every GitHub HTML page as <literal>owner</literal>/<literal>repo</literal>. <literal>rev</literal> corresponds to the Git commit hash or tag (e.g <literal>v1.0</literal>) that will be downloaded from Git. Finally, <literal>sha256</literal> corresponds to the hash of the extracted directory. Again, other hash algorithms are also available but <literal>sha256</literal> is currently preferred.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>fetchFromGitLab</literal>
+   </term>
+   <listitem>
+    <para>
+     This is used with GitLab repositories. The arguments expected are very similar to fetchFromGitHub above.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>fetchFromGitiles</literal>
+   </term>
+   <listitem>
+    <para>
+     This is used with Gitiles repositories. The arguments expected
+     are similar to fetchgit.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>fetchFromBitbucket</literal>
+   </term>
+   <listitem>
+    <para>
+     This is used with BitBucket repositories. The arguments expected are very similar to fetchFromGitHub above.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>fetchFromSavannah</literal>
+   </term>
+   <listitem>
+    <para>
+     This is used with Savannah repositories. The arguments expected are very similar to fetchFromGitHub above.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>fetchFromRepoOrCz</literal>
+   </term>
+   <listitem>
+    <para>
+     This is used with repo.or.cz repositories. The arguments expected are very similar to fetchFromGitHub above.
+    </para>
+   </listitem>
+  </varlistentry>
+ </variablelist>
+</chapter>

sources/nixpkgs/doc/builders/images.xml

@@ -0,0 +1,12 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="chap-images">
+ <title>Images</title>
+ <para>
+  This chapter describes tools for creating various types of images.
+ </para>
+ <xi:include href="images/appimagetools.xml" />
+ <xi:include href="images/dockertools.xml" />
+ <xi:include href="images/ocitools.xml" />
+ <xi:include href="images/snaptools.xml" />
+</chapter>

sources/nixpkgs/doc/builders/images/appimagetools.xml

@@ -0,0 +1,102 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-pkgs-appimageTools">
+ <title>pkgs.appimageTools</title>
+
+ <para>
+  <varname>pkgs.appimageTools</varname> is a set of functions for extracting and wrapping <link xlink:href="https://appimage.org/">AppImage</link> files. They are meant to be used if traditional packaging from source is infeasible, or it would take too long. To quickly run an AppImage file, <literal>pkgs.appimage-run</literal> can be used as well.
+ </para>
+
+ <warning>
+  <para>
+   The <varname>appimageTools</varname> API is unstable and may be subject to backwards-incompatible changes in the future.
+  </para>
+ </warning>
+
+ <section xml:id="ssec-pkgs-appimageTools-formats">
+  <title>AppImage formats</title>
+
+  <para>
+   There are different formats for AppImages, see <link xlink:href="https://github.com/AppImage/AppImageSpec/blob/74ad9ca2f94bf864a4a0dac1f369dd4f00bd1c28/draft.md#image-format">the specification</link> for details.
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Type 1 images are ISO 9660 files that are also ELF executables.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Type 2 images are ELF executables with an appended filesystem.
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <para>
+   They can be told apart with <command>file -k</command>:
+  </para>
+
+<screen>
+<prompt>$ </prompt>file -k type1.AppImage
+type1.AppImage: ELF 64-bit LSB executable, x86-64, version 1 (SYSV) ISO 9660 CD-ROM filesystem data 'AppImage' (Lepton 3.x), scale 0-0,
+spot sensor temperature 0.000000, unit celsius, color scheme 0, calibration: offset 0.000000, slope 0.000000, dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.18, BuildID[sha1]=d629f6099d2344ad82818172add1d38c5e11bc6d, stripped\012- data
+
+<prompt>$ </prompt>file -k type2.AppImage
+type2.AppImage: ELF 64-bit LSB executable, x86-64, version 1 (SYSV) (Lepton 3.x), scale 232-60668, spot sensor temperature -4.187500, color scheme 15, show scale bar, calibration: offset -0.000000, slope 0.000000 (Lepton 2.x), scale 4111-45000, spot sensor temperature 412442.250000, color scheme 3, minimum point enabled, calibration: offset -75402534979642766821519867692934234112.000000, slope 5815371847733706829839455140374904832.000000, dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.18, BuildID[sha1]=79dcc4e55a61c293c5e19edbd8d65b202842579f, stripped\012- data
+</screen>
+
+  <para>
+   Note how the type 1 AppImage is described as an <literal>ISO 9660 CD-ROM filesystem</literal>, and the type 2 AppImage is not.
+  </para>
+ </section>
+
+ <section xml:id="ssec-pkgs-appimageTools-wrapping">
+  <title>Wrapping</title>
+
+  <para>
+   Depending on the type of AppImage you're wrapping, you'll have to use <varname>wrapType1</varname> or <varname>wrapType2</varname>.
+  </para>
+
+<programlisting>
+appimageTools.wrapType2 { # or wrapType1
+  name = "patchwork"; <co xml:id='ex-appimageTools-wrapping-1' />
+  src = fetchurl { <co xml:id='ex-appimageTools-wrapping-2' />
+    url = https://github.com/ssbc/patchwork/releases/download/v3.11.4/Patchwork-3.11.4-linux-x86_64.AppImage;
+    sha256 =  "1blsprpkvm0ws9b96gb36f0rbf8f5jgmw4x6dsb1kswr4ysf591s";
+  };
+  extraPkgs = pkgs: with pkgs; [ ]; <co xml:id='ex-appimageTools-wrapping-3' />
+}</programlisting>
+
+  <calloutlist>
+   <callout arearefs='ex-appimageTools-wrapping-1'>
+    <para>
+     <varname>name</varname> specifies the name of the resulting image.
+    </para>
+   </callout>
+   <callout arearefs='ex-appimageTools-wrapping-2'>
+    <para>
+     <varname>src</varname> specifies the AppImage file to extract.
+    </para>
+   </callout>
+   <callout arearefs='ex-appimageTools-wrapping-2'>
+    <para>
+     <varname>extraPkgs</varname> allows you to pass a function to include additional packages inside the FHS environment your AppImage is going to run in. There are a few ways to learn which dependencies an application needs:
+     <itemizedlist>
+      <listitem>
+       <para>
+        Looking through the extracted AppImage files, reading its scripts and running <command>patchelf</command> and <command>ldd</command> on its executables. This can also be done in <command>appimage-run</command>, by setting <command>APPIMAGE_DEBUG_EXEC=bash</command>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Running <command>strace -vfefile</command> on the wrapped executable, looking for libraries that can't be found.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </callout>
+  </calloutlist>
+ </section>
+</section>

sources/nixpkgs/doc/builders/images/dockertools.xml

@@ -0,0 +1,478 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-pkgs-dockerTools">
+ <title>pkgs.dockerTools</title>
+
+ <para>
+  <varname>pkgs.dockerTools</varname> is a set of functions for creating and manipulating Docker images according to the <link xlink:href="https://github.com/moby/moby/blob/master/image/spec/v1.2.md#docker-image-specification-v120"> Docker Image Specification v1.2.0 </link>. Docker itself is not used to perform any of the operations done by these functions.
+ </para>
+
+ <section xml:id="ssec-pkgs-dockerTools-buildImage">
+  <title>buildImage</title>
+
+  <para>
+   This function is analogous to the <command>docker build</command> command, in that it can be used to build a Docker-compatible repository tarball containing a single image with one or multiple layers. As such, the result is suitable for being loaded in Docker with <command>docker load</command>.
+  </para>
+
+  <para>
+   The parameters of <varname>buildImage</varname> with relative example values are described below:
+  </para>
+
+  <example xml:id='ex-dockerTools-buildImage'>
+   <title>Docker build</title>
+<programlisting>
+buildImage {
+  name = "redis"; <co xml:id='ex-dockerTools-buildImage-1' />
+  tag = "latest"; <co xml:id='ex-dockerTools-buildImage-2' />
+
+  fromImage = someBaseImage; <co xml:id='ex-dockerTools-buildImage-3' />
+  fromImageName = null; <co xml:id='ex-dockerTools-buildImage-4' />
+  fromImageTag = "latest"; <co xml:id='ex-dockerTools-buildImage-5' />
+
+  contents = pkgs.redis; <co xml:id='ex-dockerTools-buildImage-6' />
+  runAsRoot = '' <co xml:id='ex-dockerTools-buildImage-runAsRoot' />
+    #!${pkgs.runtimeShell}
+    mkdir -p /data
+  '';
+
+  config = { <co xml:id='ex-dockerTools-buildImage-8' />
+    Cmd = [ "/bin/redis-server" ];
+    WorkingDir = "/data";
+    Volumes = {
+      "/data" = {};
+    };
+  };
+}
+</programlisting>
+  </example>
+
+  <para>
+   The above example will build a Docker image <literal>redis/latest</literal> from the given base image. Loading and running this image in Docker results in <literal>redis-server</literal> being started automatically.
+  </para>
+
+  <calloutlist>
+   <callout arearefs='ex-dockerTools-buildImage-1'>
+    <para>
+     <varname>name</varname> specifies the name of the resulting image. This is the only required argument for <varname>buildImage</varname>.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-2'>
+    <para>
+     <varname>tag</varname> specifies the tag of the resulting image. By default it's <literal>null</literal>, which indicates that the nix output hash will be used as tag.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-3'>
+    <para>
+     <varname>fromImage</varname> is the repository tarball containing the base image. It must be a valid Docker image, such as exported by <command>docker save</command>. By default it's <literal>null</literal>, which can be seen as equivalent to <literal>FROM scratch</literal> of a <filename>Dockerfile</filename>.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-4'>
+    <para>
+     <varname>fromImageName</varname> can be used to further specify the base image within the repository, in case it contains multiple images. By default it's <literal>null</literal>, in which case <varname>buildImage</varname> will peek the first image available in the repository.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-5'>
+    <para>
+     <varname>fromImageTag</varname> can be used to further specify the tag of the base image within the repository, in case an image contains multiple tags. By default it's <literal>null</literal>, in which case <varname>buildImage</varname> will peek the first tag available for the base image.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-6'>
+    <para>
+     <varname>contents</varname> is a derivation that will be copied in the new layer of the resulting image. This can be similarly seen as <command>ADD contents/ /</command> in a <filename>Dockerfile</filename>. By default it's <literal>null</literal>.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-runAsRoot'>
+    <para>
+     <varname>runAsRoot</varname> is a bash script that will run as root in an environment that overlays the existing layers of the base image with the new resulting layer, including the previously copied <varname>contents</varname> derivation. This can be similarly seen as <command>RUN ...</command> in a <filename>Dockerfile</filename>.
+     <note>
+      <para>
+       Using this parameter requires the <literal>kvm</literal> device to be available.
+      </para>
+     </note>
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-8'>
+    <para>
+     <varname>config</varname> is used to specify the configuration of the containers that will be started off the built image in Docker. The available options are listed in the <link xlink:href="https://github.com/moby/moby/blob/master/image/spec/v1.2.md#image-json-field-descriptions"> Docker Image Specification v1.2.0 </link>.
+    </para>
+   </callout>
+  </calloutlist>
+
+  <para>
+   After the new layer has been created, its closure (to which <varname>contents</varname>, <varname>config</varname> and <varname>runAsRoot</varname> contribute) will be copied in the layer itself. Only new dependencies that are not already in the existing layers will be copied.
+  </para>
+
+  <para>
+   At the end of the process, only one new single layer will be produced and added to the resulting image.
+  </para>
+
+  <para>
+   The resulting repository will only list the single image <varname>image/tag</varname>. In the case of <xref linkend='ex-dockerTools-buildImage'/> it would be <varname>redis/latest</varname>.
+  </para>
+
+  <para>
+   It is possible to inspect the arguments with which an image was built using its <varname>buildArgs</varname> attribute.
+  </para>
+
+  <note>
+   <para>
+    If you see errors similar to <literal>getProtocolByName: does not exist (no such protocol name: tcp)</literal> you may need to add <literal>pkgs.iana-etc</literal> to <varname>contents</varname>.
+   </para>
+  </note>
+
+  <note>
+   <para>
+    If you see errors similar to <literal>Error_Protocol ("certificate has unknown CA",True,UnknownCa)</literal> you may need to add <literal>pkgs.cacert</literal> to <varname>contents</varname>.
+   </para>
+  </note>
+
+  <example xml:id="example-pkgs-dockerTools-buildImage-creation-date">
+   <title>Impurely Defining a Docker Layer's Creation Date</title>
+   <para>
+    By default <function>buildImage</function> will use a static date of one second past the UNIX Epoch. This allows <function>buildImage</function> to produce binary reproducible images. When listing images with <command>docker images</command>, the newly created images will be listed like this:
+   </para>
+<screen><![CDATA[
+$ docker images
+REPOSITORY   TAG      IMAGE ID       CREATED        SIZE
+hello        latest   08c791c7846e   48 years ago   25.2MB
+]]></screen>
+   <para>
+    You can break binary reproducibility but have a sorted, meaningful <literal>CREATED</literal> column by setting <literal>created</literal> to <literal>now</literal>.
+   </para>
+<programlisting><![CDATA[
+pkgs.dockerTools.buildImage {
+  name = "hello";
+  tag = "latest";
+  created = "now";
+  contents = pkgs.hello;
+
+  config.Cmd = [ "/bin/hello" ];
+}
+]]></programlisting>
+   <para>
+    and now the Docker CLI will display a reasonable date and sort the images as expected:
+<screen><![CDATA[
+$ docker images
+REPOSITORY   TAG      IMAGE ID       CREATED              SIZE
+hello        latest   de2bf4786de6   About a minute ago   25.2MB
+]]></screen>
+    however, the produced images will not be binary reproducible.
+   </para>
+  </example>
+ </section>
+
+ <section xml:id="ssec-pkgs-dockerTools-buildLayeredImage">
+  <title>buildLayeredImage</title>
+
+  <para>
+   Create a Docker image with many of the store paths being on their own layer to improve sharing between images.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>name</varname>
+    </term>
+    <listitem>
+     <para>
+      The name of the resulting image.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>tag</varname> <emphasis>optional</emphasis>
+    </term>
+    <listitem>
+     <para>
+      Tag of the generated image.
+     </para>
+     <para>
+      <emphasis>Default:</emphasis> the output path's hash
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>contents</varname> <emphasis>optional</emphasis>
+    </term>
+    <listitem>
+     <para>
+      Top level paths in the container. Either a single derivation, or a list of derivations.
+     </para>
+     <para>
+      <emphasis>Default:</emphasis> <literal>[]</literal>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>config</varname> <emphasis>optional</emphasis>
+    </term>
+    <listitem>
+     <para>
+      Run-time configuration of the container. A full list of the options are available at in the <link xlink:href="https://github.com/moby/moby/blob/master/image/spec/v1.2.md#image-json-field-descriptions"> Docker Image Specification v1.2.0 </link>.
+     </para>
+     <para>
+      <emphasis>Default:</emphasis> <literal>{}</literal>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>created</varname> <emphasis>optional</emphasis>
+    </term>
+    <listitem>
+     <para>
+      Date and time the layers were created. Follows the same <literal>now</literal> exception supported by <literal>buildImage</literal>.
+     </para>
+     <para>
+      <emphasis>Default:</emphasis> <literal>1970-01-01T00:00:01Z</literal>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>maxLayers</varname> <emphasis>optional</emphasis>
+    </term>
+    <listitem>
+     <para>
+      Maximum number of layers to create.
+     </para>
+     <para>
+      <emphasis>Default:</emphasis> <literal>100</literal>
+     </para>
+     <para>
+      <emphasis>Maximum:</emphasis> <literal>125</literal>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>extraCommands</varname> <emphasis>optional</emphasis>
+    </term>
+    <listitem>
+     <para>
+      Shell commands to run while building the final layer, without access to most of the layer contents. Changes to this layer are "on top" of all the other layers, so can create additional directories and files.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <section xml:id="dockerTools-buildLayeredImage-arg-contents">
+   <title>Behavior of <varname>contents</varname> in the final image</title>
+
+   <para>
+    Each path directly listed in <varname>contents</varname> will have a symlink in the root of the image.
+   </para>
+
+   <para>
+    For example:
+<programlisting><![CDATA[
+pkgs.dockerTools.buildLayeredImage {
+  name = "hello";
+  contents = [ pkgs.hello ];
+}
+]]></programlisting>
+    will create symlinks for all the paths in the <literal>hello</literal> package:
+<screen><![CDATA[
+/bin/hello -> /nix/store/h1zb1padqbbb7jicsvkmrym3r6snphxg-hello-2.10/bin/hello
+/share/info/hello.info -> /nix/store/h1zb1padqbbb7jicsvkmrym3r6snphxg-hello-2.10/share/info/hello.info
+/share/locale/bg/LC_MESSAGES/hello.mo -> /nix/store/h1zb1padqbbb7jicsvkmrym3r6snphxg-hello-2.10/share/locale/bg/LC_MESSAGES/hello.mo
+]]></screen>
+   </para>
+  </section>
+
+  <section xml:id="dockerTools-buildLayeredImage-arg-config">
+   <title>Automatic inclusion of <varname>config</varname> references</title>
+
+   <para>
+    The closure of <varname>config</varname> is automatically included in the closure of the final image.
+   </para>
+
+   <para>
+    This allows you to make very simple Docker images with very little code. This container will start up and run <command>hello</command>:
+<programlisting><![CDATA[
+pkgs.dockerTools.buildLayeredImage {
+  name = "hello";
+  config.Cmd = [ "${pkgs.hello}/bin/hello" ];
+}
+]]></programlisting>
+   </para>
+  </section>
+
+  <section xml:id="dockerTools-buildLayeredImage-arg-maxLayers">
+   <title>Adjusting <varname>maxLayers</varname></title>
+
+   <para>
+    Increasing the <varname>maxLayers</varname> increases the number of layers which have a chance to be shared between different images.
+   </para>
+
+   <para>
+    Modern Docker installations support up to 128 layers, however older versions support as few as 42.
+   </para>
+
+   <para>
+    If the produced image will not be extended by other Docker builds, it is safe to set <varname>maxLayers</varname> to <literal>128</literal>. However it will be impossible to extend the image further.
+   </para>
+
+   <para>
+    The first (<literal>maxLayers-2</literal>) most "popular" paths will have their own individual layers, then layer #<literal>maxLayers-1</literal> will contain all the remaining "unpopular" paths, and finally layer #<literal>maxLayers</literal> will contain the Image configuration.
+   </para>
+
+   <para>
+    Docker's Layers are not inherently ordered, they are content-addressable and are not explicitly layered until they are composed in to an Image.
+   </para>
+  </section>
+ </section>
+
+ <section xml:id="ssec-pkgs-dockerTools-fetchFromRegistry">
+  <title>pullImage</title>
+
+  <para>
+   This function is analogous to the <command>docker pull</command> command, in that it can be used to pull a Docker image from a Docker registry. By default <link xlink:href="https://hub.docker.com/">Docker Hub</link> is used to pull images.
+  </para>
+
+  <para>
+   Its parameters are described in the example below:
+  </para>
+
+  <example xml:id='ex-dockerTools-pullImage'>
+   <title>Docker pull</title>
+<programlisting>
+pullImage {
+  imageName = "nixos/nix"; <co xml:id='ex-dockerTools-pullImage-1' />
+  imageDigest = "sha256:20d9485b25ecfd89204e843a962c1bd70e9cc6858d65d7f5fadc340246e2116b"; <co xml:id='ex-dockerTools-pullImage-2' />
+  finalImageName = "nix"; <co xml:id='ex-dockerTools-pullImage-3' />
+  finalImageTag = "1.11";  <co xml:id='ex-dockerTools-pullImage-4' />
+  sha256 = "0mqjy3zq2v6rrhizgb9nvhczl87lcfphq9601wcprdika2jz7qh8"; <co xml:id='ex-dockerTools-pullImage-5' />
+  os = "linux"; <co xml:id='ex-dockerTools-pullImage-6' />
+  arch = "x86_64"; <co xml:id='ex-dockerTools-pullImage-7' />
+}
+</programlisting>
+  </example>
+
+  <calloutlist>
+   <callout arearefs='ex-dockerTools-pullImage-1'>
+    <para>
+     <varname>imageName</varname> specifies the name of the image to be downloaded, which can also include the registry namespace (e.g. <literal>nixos</literal>). This argument is required.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-pullImage-2'>
+    <para>
+     <varname>imageDigest</varname> specifies the digest of the image to be downloaded. This argument is required.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-pullImage-3'>
+    <para>
+     <varname>finalImageName</varname>, if specified, this is the name of the image to be created. Note it is never used to fetch the image since we prefer to rely on the immutable digest ID. By default it's equal to <varname>imageName</varname>.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-pullImage-4'>
+    <para>
+     <varname>finalImageTag</varname>, if specified, this is the tag of the image to be created. Note it is never used to fetch the image since we prefer to rely on the immutable digest ID. By default it's <literal>latest</literal>.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-pullImage-5'>
+    <para>
+     <varname>sha256</varname> is the checksum of the whole fetched image. This argument is required.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-pullImage-6'>
+    <para>
+     <varname>os</varname>, if specified, is the operating system of the fetched image. By default it's <literal>linux</literal>.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-pullImage-7'>
+    <para>
+     <varname>arch</varname>, if specified, is the cpu architecture of the fetched image. By default it's <literal>x86_64</literal>.
+    </para>
+   </callout>
+  </calloutlist>
+
+  <para>
+   <literal>nix-prefetch-docker</literal> command can be used to get required image parameters:
+<screen>
+<prompt>$ </prompt>nix run nixpkgs.nix-prefetch-docker -c nix-prefetch-docker --image-name mysql --image-tag 5
+</screen>
+   Since a given <varname>imageName</varname> may transparently refer to a manifest list of images which support multiple architectures and/or operating systems, you can supply the <option>--os</option> and <option>--arch</option> arguments to specify exactly which image you want. By default it will match the OS and architecture of the host the command is run on.
+<screen>
+<prompt>$ </prompt>nix-prefetch-docker --image-name mysql --image-tag 5 --arch x86_64 --os linux
+</screen>
+   Desired image name and tag can be set using <option>--final-image-name</option> and <option>--final-image-tag</option> arguments:
+<screen>
+<prompt>$ </prompt>nix-prefetch-docker --image-name mysql --image-tag 5 --final-image-name eu.gcr.io/my-project/mysql --final-image-tag prod
+</screen>
+  </para>
+ </section>
+
+ <section xml:id="ssec-pkgs-dockerTools-exportImage">
+  <title>exportImage</title>
+
+  <para>
+   This function is analogous to the <command>docker export</command> command, in that it can be used to flatten a Docker image that contains multiple layers. It is in fact the result of the merge of all the layers of the image. As such, the result is suitable for being imported in Docker with <command>docker import</command>.
+  </para>
+
+  <note>
+   <para>
+    Using this function requires the <literal>kvm</literal> device to be available.
+   </para>
+  </note>
+
+  <para>
+   The parameters of <varname>exportImage</varname> are the following:
+  </para>
+
+  <example xml:id='ex-dockerTools-exportImage'>
+   <title>Docker export</title>
+<programlisting>
+exportImage {
+  fromImage = someLayeredImage;
+  fromImageName = null;
+  fromImageTag = null;
+
+  name = someLayeredImage.name;
+}
+</programlisting>
+  </example>
+
+  <para>
+   The parameters relative to the base image have the same synopsis as described in <xref linkend='ssec-pkgs-dockerTools-buildImage'/>, except that <varname>fromImage</varname> is the only required argument in this case.
+  </para>
+
+  <para>
+   The <varname>name</varname> argument is the name of the derivation output, which defaults to <varname>fromImage.name</varname>.
+  </para>
+ </section>
+
+ <section xml:id="ssec-pkgs-dockerTools-shadowSetup">
+  <title>shadowSetup</title>
+
+  <para>
+   This constant string is a helper for setting up the base files for managing users and groups, only if such files don't exist already. It is suitable for being used in a <varname>runAsRoot</varname> <xref linkend='ex-dockerTools-buildImage-runAsRoot'/> script for cases like in the example below:
+  </para>
+
+  <example xml:id='ex-dockerTools-shadowSetup'>
+   <title>Shadow base files</title>
+<programlisting>
+buildImage {
+  name = "shadow-basic";
+
+  runAsRoot = ''
+    #!${pkgs.runtimeShell}
+    ${shadowSetup}
+    groupadd -r redis
+    useradd -r -g redis redis
+    mkdir /data
+    chown redis:redis /data
+  '';
+}
+</programlisting>
+  </example>
+
+  <para>
+   Creating base files like <literal>/etc/passwd</literal> or <literal>/etc/login.defs</literal> is necessary for shadow-utils to manipulate users and groups.
+  </para>
+ </section>
+</section>

sources/nixpkgs/doc/builders/images/ocitools.xml

@@ -0,0 +1,62 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-pkgs-ociTools">
+ <title>pkgs.ociTools</title>
+
+ <para>
+  <varname>pkgs.ociTools</varname> is a set of functions for creating containers according to the <link xlink:href="https://github.com/opencontainers/runtime-spec">OCI container specification v1.0.0</link>. Beyond that it makes no assumptions about the container runner you choose to use to run the created container.
+ </para>
+
+ <section xml:id="ssec-pkgs-ociTools-buildContainer">
+  <title>buildContainer</title>
+
+  <para>
+   This function creates a simple OCI container that runs a single command inside of it. An OCI container consists of a <varname>config.json</varname> and a rootfs directory.The nix store of the container will contain all referenced dependencies of the given command.
+  </para>
+
+  <para>
+   The parameters of <varname>buildContainer</varname> with an example value are described below:
+  </para>
+
+  <example xml:id='ex-ociTools-buildContainer'>
+   <title>Build Container</title>
+<programlisting>
+buildContainer {
+  args = [ (with pkgs; writeScript "run.sh" ''
+    #!${bash}/bin/bash
+    ${coreutils}/bin/exec ${bash}/bin/bash
+  '').outPath ]; <co xml:id='ex-ociTools-buildContainer-1' />
+
+  mounts = {
+    "/data" = {
+      type = "none";
+      source = "/var/lib/mydata";
+      options = [ "bind" ];
+    };
+  };<co xml:id='ex-ociTools-buildContainer-2' />
+
+  readonly = false; <co xml:id='ex-ociTools-buildContainer-3' />
+}
+
+    </programlisting>
+   <calloutlist>
+    <callout arearefs='ex-ociTools-buildContainer-1'>
+     <para>
+      <varname>args</varname> specifies a set of arguments to run inside the container. This is the only required argument for <varname>buildContainer</varname>. All referenced packages inside the derivation will be made available inside the container
+     </para>
+    </callout>
+    <callout arearefs='ex-ociTools-buildContainer-2'>
+     <para>
+      <varname>mounts</varname> specifies additional mount points chosen by the user. By default only a minimal set of necessary filesystems are mounted into the container (e.g procfs, cgroupfs)
+     </para>
+    </callout>
+    <callout arearefs='ex-ociTools-buildContainer-3'>
+     <para>
+      <varname>readonly</varname> makes the container's rootfs read-only if it is set to true. The default value is false <literal>false</literal>.
+     </para>
+    </callout>
+   </calloutlist>
+  </example>
+ </section>
+</section>

sources/nixpkgs/doc/builders/images/snap/example-firefox.nix

@@ -0,0 +1,28 @@
+let
+  inherit (import <nixpkgs> { }) snapTools firefox;
+in snapTools.makeSnap {
+  meta = {
+    name = "nix-example-firefox";
+    summary = firefox.meta.description;
+    architectures = [ "amd64" ];
+    apps.nix-example-firefox = {
+      command = "${firefox}/bin/firefox";
+      plugs = [
+        "pulseaudio"
+        "camera"
+        "browser-support"
+        "avahi-observe"
+        "cups-control"
+        "desktop"
+        "desktop-legacy"
+        "gsettings"
+        "home"
+        "network"
+        "mount-observe"
+        "removable-media"
+        "x11"
+      ];
+    };
+    confinement = "strict";
+  };
+}

sources/nixpkgs/doc/builders/images/snap/example-hello.nix

@@ -0,0 +1,12 @@
+let
+  inherit (import <nixpkgs> { }) snapTools hello;
+in snapTools.makeSnap {
+  meta = {
+    name = "hello";
+    summary = hello.meta.description;
+    description = hello.meta.longDescription;
+    architectures = [ "amd64" ];
+    confinement = "strict";
+    apps.hello.command = "${hello}/bin/hello";
+  };
+}

sources/nixpkgs/doc/builders/images/snaptools.xml

@@ -0,0 +1,59 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-pkgs-snapTools">
+ <title>pkgs.snapTools</title>
+
+ <para>
+  <varname>pkgs.snapTools</varname> is a set of functions for creating Snapcraft images. Snap and Snapcraft is not used to perform these operations.
+ </para>
+
+ <section xml:id="ssec-pkgs-snapTools-makeSnap-signature">
+  <title>The makeSnap Function</title>
+
+  <para>
+   <function>makeSnap</function> takes a single named argument, <parameter>meta</parameter>. This argument mirrors <link xlink:href="https://docs.snapcraft.io/snap-format">the upstream <filename>snap.yaml</filename> format</link> exactly.
+  </para>
+
+  <para>
+   The <parameter>base</parameter> should not be be specified, as <function>makeSnap</function> will force set it.
+  </para>
+
+  <para>
+   Currently, <function>makeSnap</function> does not support creating GUI stubs.
+  </para>
+ </section>
+
+ <section xml:id="ssec-pkgs-snapTools-build-a-snap-hello">
+  <title>Build a Hello World Snap</title>
+
+  <example xml:id="ex-snapTools-buildSnap-hello">
+   <title>Making a Hello World Snap</title>
+   <para>
+    The following expression packages GNU Hello as a Snapcraft snap.
+   </para>
+<programlisting><xi:include href="./snap/example-hello.nix" parse="text" /></programlisting>
+   <para>
+    <command>nix-build</command> this expression and install it with <command>snap install ./result --dangerous</command>. <command>hello</command> will now be the Snapcraft version of the package.
+   </para>
+  </example>
+ </section>
+
+ <section xml:id="ssec-pkgs-snapTools-build-a-snap-firefox">
+  <title>Build a Hello World Snap</title>
+
+  <example xml:id="ex-snapTools-buildSnap-firefox">
+   <title>Making a Graphical Snap</title>
+   <para>
+    Graphical programs require many more integrations with the host. This example uses Firefox as an example, because it is one of the most complicated programs we could package.
+   </para>
+<programlisting><xi:include href="./snap/example-firefox.nix" parse="text" /></programlisting>
+   <para>
+    <command>nix-build</command> this expression and install it with <command>snap install ./result --dangerous</command>. <command>nix-example-firefox</command> will now be the Snapcraft version of the Firefox package.
+   </para>
+   <para>
+    The specific meaning behind plugs can be looked up in the <link xlink:href="https://docs.snapcraft.io/supported-interfaces">Snapcraft interface documentation</link>.
+   </para>
+  </example>
+ </section>
+</section>

sources/nixpkgs/doc/builders/packages/citrix.xml

@@ -0,0 +1,44 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-citrix">
+ <title>Citrix Workspace</title>
+
+ <para>
+  <note>
+   <para>
+    Please note that the <literal>citrix_receiver</literal> package has been deprecated since its development was <link xlink:href="https://docs.citrix.com/en-us/citrix-workspace-app.html">discontinued by upstream</link> and has been replaced by <link xlink:href="https://www.citrix.com/products/workspace-app/">the citrix workspace app</link>.
+   </para>
+  </note>
+  <link xlink:href="https://www.citrix.com/products/receiver/">Citrix Receiver</link> and <link xlink:href="https://www.citrix.com/products/workspace-app/">Citrix Workspace App</link> are a remote desktop viewers which provide access to <link xlink:href="https://www.citrix.com/products/xenapp-xendesktop/">XenDesktop</link> installations.
+ </para>
+
+ <section xml:id="sec-citrix-base">
+  <title>Basic usage</title>
+
+  <para>
+   The tarball archive needs to be downloaded manually as the license agreements of the vendor for <link xlink:href="https://www.citrix.com/downloads/citrix-receiver/">Citrix Receiver</link> or <link xlink:href="https://www.citrix.de/downloads/workspace-app/linux/workspace-app-for-linux-latest.html">Citrix Workspace</link> need to be accepted first. Then run <command>nix-prefetch-url file://$PWD/linuxx64-$version.tar.gz</command>. With the archive available in the store the package can be built and installed with Nix.
+  </para>
+
+  <warning>
+   <title>Caution with <command>nix-shell</command> installs</title>
+   <para>
+    It's recommended to install <literal>Citrix Receiver</literal> and/or <literal>Citrix Workspace</literal> using <literal>nix-env -i</literal> or globally to ensure that the <literal>.desktop</literal> files are installed properly into <literal>$XDG_CONFIG_DIRS</literal>. Otherwise it won't be possible to open <literal>.ica</literal> files automatically from the browser to start a Citrix connection.
+   </para>
+  </warning>
+ </section>
+
+ <section xml:id="sec-citrix-custom-certs">
+  <title>Custom certificates</title>
+
+  <para>
+   The <literal>Citrix Workspace App</literal> in <literal>nixpkgs</literal> trust several certificates <link xlink:href="https://curl.haxx.se/docs/caextract.html">from the Mozilla database</link> by default. However several companies using Citrix might require their own corporate certificate. On distros with imperative packaging these certs can be stored easily in <link xlink:href="https://developer-docs.citrix.com/projects/receiver-for-linux-command-reference/en/13.7/"><literal>$ICAROOT</literal></link>, however this directory is a store path in <literal>nixpkgs</literal>. In order to work around this issue the package provides a simple mechanism to add custom certificates without rebuilding the entire package using <literal>symlinkJoin</literal>:
+<programlisting>
+<![CDATA[with import <nixpkgs> { config.allowUnfree = true; };
+let extraCerts = [ ./custom-cert-1.pem ./custom-cert-2.pem /* ... */ ]; in
+citrix_workspace.override {
+  inherit extraCerts;
+}]]>
+</programlisting>
+  </para>
+ </section>
+</section>

sources/nixpkgs/doc/builders/packages/dlib.xml

@@ -0,0 +1,24 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="dlib">
+ <title>DLib</title>
+
+ <para>
+  <link xlink:href="http://dlib.net/">DLib</link> is a modern, C++-based toolkit which provides several machine learning algorithms.
+ </para>
+
+ <section xml:id="compiling-without-avx-support">
+  <title>Compiling without AVX support</title>
+
+  <para>
+   Especially older CPUs don't support <link xlink:href="https://en.wikipedia.org/wiki/Advanced_Vector_Extensions">AVX</link> (<abbrev>Advanced Vector Extensions</abbrev>) instructions that are used by DLib to optimize their algorithms.
+  </para>
+
+  <para>
+   On the affected hardware errors like <literal>Illegal instruction</literal> will occur. In those cases AVX support needs to be disabled:
+<programlisting>self: super: {
+  dlib = super.dlib.override { avxSupport = false; };
+}</programlisting>
+  </para>
+ </section>
+</section>

sources/nixpkgs/doc/builders/packages/eclipse.xml

@@ -0,0 +1,72 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-eclipse">
+ <title>Eclipse</title>
+
+ <para>
+  The Nix expressions related to the Eclipse platform and IDE are in <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/eclipse"><filename>pkgs/applications/editors/eclipse</filename></link>.
+ </para>
+
+ <para>
+  Nixpkgs provides a number of packages that will install Eclipse in its various forms. These range from the bare-bones Eclipse Platform to the more fully featured Eclipse SDK or Scala-IDE packages and multiple version are often available. It is possible to list available Eclipse packages by issuing the command:
+<screen>
+<prompt>$ </prompt>nix-env -f '&lt;nixpkgs&gt;' -qaP -A eclipses --description
+</screen>
+  Once an Eclipse variant is installed it can be run using the <command>eclipse</command> command, as expected. From within Eclipse it is then possible to install plugins in the usual manner by either manually specifying an Eclipse update site or by installing the Marketplace Client plugin and using it to discover and install other plugins. This installation method provides an Eclipse installation that closely resemble a manually installed Eclipse.
+ </para>
+
+ <para>
+  If you prefer to install plugins in a more declarative manner then Nixpkgs also offer a number of Eclipse plugins that can be installed in an <emphasis>Eclipse environment</emphasis>. This type of environment is created using the function <varname>eclipseWithPlugins</varname> found inside the <varname>nixpkgs.eclipses</varname> attribute set. This function takes as argument <literal>{ eclipse, plugins ? [], jvmArgs ? [] }</literal> where <varname>eclipse</varname> is a one of the Eclipse packages described above, <varname>plugins</varname> is a list of plugin derivations, and <varname>jvmArgs</varname> is a list of arguments given to the JVM running the Eclipse. For example, say you wish to install the latest Eclipse Platform with the popular Eclipse Color Theme plugin and also allow Eclipse to use more RAM. You could then add
+<screen>
+packageOverrides = pkgs: {
+  myEclipse = with pkgs.eclipses; eclipseWithPlugins {
+    eclipse = eclipse-platform;
+    jvmArgs = [ "-Xmx2048m" ];
+    plugins = [ plugins.color-theme ];
+  };
+}
+</screen>
+  to your Nixpkgs configuration (<filename>~/.config/nixpkgs/config.nix</filename>) and install it by running <command>nix-env -f '&lt;nixpkgs&gt;' -iA myEclipse</command> and afterward run Eclipse as usual. It is possible to find out which plugins are available for installation using <varname>eclipseWithPlugins</varname> by running
+<screen>
+<prompt>$ </prompt>nix-env -f '&lt;nixpkgs&gt;' -qaP -A eclipses.plugins --description
+</screen>
+ </para>
+
+ <para>
+  If there is a need to install plugins that are not available in Nixpkgs then it may be possible to define these plugins outside Nixpkgs using the <varname>buildEclipseUpdateSite</varname> and <varname>buildEclipsePlugin</varname> functions found in the <varname>nixpkgs.eclipses.plugins</varname> attribute set. Use the <varname>buildEclipseUpdateSite</varname> function to install a plugin distributed as an Eclipse update site. This function takes <literal>{ name, src }</literal> as argument where <literal>src</literal> indicates the Eclipse update site archive. All Eclipse features and plugins within the downloaded update site will be installed. When an update site archive is not available then the <varname>buildEclipsePlugin</varname> function can be used to install a plugin that consists of a pair of feature and plugin JARs. This function takes an argument <literal>{ name, srcFeature, srcPlugin }</literal> where <literal>srcFeature</literal> and <literal>srcPlugin</literal> are the feature and plugin JARs, respectively.
+ </para>
+
+ <para>
+  Expanding the previous example with two plugins using the above functions we have
+<screen>
+packageOverrides = pkgs: {
+  myEclipse = with pkgs.eclipses; eclipseWithPlugins {
+    eclipse = eclipse-platform;
+    jvmArgs = [ "-Xmx2048m" ];
+    plugins = [
+      plugins.color-theme
+      (plugins.buildEclipsePlugin {
+        name = "myplugin1-1.0";
+        srcFeature = fetchurl {
+          url = "http://…/features/myplugin1.jar";
+          sha256 = "123…";
+        };
+        srcPlugin = fetchurl {
+          url = "http://…/plugins/myplugin1.jar";
+          sha256 = "123…";
+        };
+      });
+      (plugins.buildEclipseUpdateSite {
+        name = "myplugin2-1.0";
+        src = fetchurl {
+          stripRoot = false;
+          url = "http://…/myplugin2.zip";
+          sha256 = "123…";
+        };
+      });
+    ];
+  };
+}
+</screen>
+ </para>
+</section>

sources/nixpkgs/doc/builders/packages/elm.xml

@@ -0,0 +1,17 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-elm">
+ <title>Elm</title>
+
+ <para>
+  To start a development environment do <command>nix-shell -p elmPackages.elm elmPackages.elm-format</command>
+ </para>
+
+ <para>
+  To update Elm compiler, see <filename>nixpkgs/pkgs/development/compilers/elm/README.md</filename>.
+ </para>
+
+ <para>
+  To package Elm applications, <link xlink:href="https://github.com/hercules-ci/elm2nix#elm2nix">read about elm2nix</link>.
+ </para>
+</section>

sources/nixpkgs/doc/builders/packages/emacs.xml

@@ -0,0 +1,131 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-emacs">
+ <title>Emacs</title>
+
+ <section xml:id="sec-emacs-config">
+  <title>Configuring Emacs</title>
+
+  <para>
+   The Emacs package comes with some extra helpers to make it easier to configure. <varname>emacsWithPackages</varname> allows you to manage packages from ELPA. This means that you will not have to install that packages from within Emacs. For instance, if you wanted to use <literal>company</literal>, <literal>counsel</literal>, <literal>flycheck</literal>, <literal>ivy</literal>, <literal>magit</literal>, <literal>projectile</literal>, and <literal>use-package</literal> you could use this as a <filename>~/.config/nixpkgs/config.nix</filename> override:
+  </para>
+
+<screen>
+{
+  packageOverrides = pkgs: with pkgs; {
+    myEmacs = emacsWithPackages (epkgs: (with epkgs.melpaStablePackages; [
+      company
+      counsel
+      flycheck
+      ivy
+      magit
+      projectile
+      use-package
+    ]));
+  }
+}
+</screen>
+
+  <para>
+   You can install it like any other packages via <command>nix-env -iA myEmacs</command>. However, this will only install those packages. It will not <literal>configure</literal> them for us. To do this, we need to provide a configuration file. Luckily, it is possible to do this from within Nix! By modifying the above example, we can make Emacs load a custom config file. The key is to create a package that provide a <filename>default.el</filename> file in <filename>/share/emacs/site-start/</filename>. Emacs knows to load this file automatically when it starts.
+  </para>
+
+<screen>
+{
+  packageOverrides = pkgs: with pkgs; rec {
+    myEmacsConfig = writeText "default.el" ''
+;; initialize package
+
+(require 'package)
+(package-initialize 'noactivate)
+(eval-when-compile
+  (require 'use-package))
+
+;; load some packages
+
+(use-package company
+  :bind ("&lt;C-tab&gt;" . company-complete)
+  :diminish company-mode
+  :commands (company-mode global-company-mode)
+  :defer 1
+  :config
+  (global-company-mode))
+
+(use-package counsel
+  :commands (counsel-descbinds)
+  :bind (([remap execute-extended-command] . counsel-M-x)
+         ("C-x C-f" . counsel-find-file)
+         ("C-c g" . counsel-git)
+         ("C-c j" . counsel-git-grep)
+         ("C-c k" . counsel-ag)
+         ("C-x l" . counsel-locate)
+         ("M-y" . counsel-yank-pop)))
+
+(use-package flycheck
+  :defer 2
+  :config (global-flycheck-mode))
+
+(use-package ivy
+  :defer 1
+  :bind (("C-c C-r" . ivy-resume)
+         ("C-x C-b" . ivy-switch-buffer)
+         :map ivy-minibuffer-map
+         ("C-j" . ivy-call))
+  :diminish ivy-mode
+  :commands ivy-mode
+  :config
+  (ivy-mode 1))
+
+(use-package magit
+  :defer
+  :if (executable-find "git")
+  :bind (("C-x g" . magit-status)
+         ("C-x G" . magit-dispatch-popup))
+  :init
+  (setq magit-completing-read-function 'ivy-completing-read))
+
+(use-package projectile
+  :commands projectile-mode
+  :bind-keymap ("C-c p" . projectile-command-map)
+  :defer 5
+  :config
+  (projectile-global-mode))
+    '';
+    myEmacs = emacsWithPackages (epkgs: (with epkgs.melpaStablePackages; [
+      (runCommand "default.el" {} ''
+mkdir -p $out/share/emacs/site-lisp
+cp ${myEmacsConfig} $out/share/emacs/site-lisp/default.el
+'')
+      company
+      counsel
+      flycheck
+      ivy
+      magit
+      projectile
+      use-package
+    ]));
+  };
+}
+</screen>
+
+  <para>
+   This provides a fairly full Emacs start file. It will load in addition to the user's presonal config. You can always disable it by passing <command>-q</command> to the Emacs command.
+  </para>
+
+  <para>
+   Sometimes <varname>emacsWithPackages</varname> is not enough, as this package set has some priorities imposed on packages (with the lowest priority assigned to Melpa Unstable, and the highest for packages manually defined in <filename>pkgs/top-level/emacs-packages.nix</filename>). But you can't control this priorities when some package is installed as a dependency. You can override it on per-package-basis, providing all the required dependencies manually - but it's tedious and there is always a possibility that an unwanted dependency will sneak in through some other package. To completely override such a package you can use <varname>overrideScope'</varname>.
+  </para>
+
+<screen>
+overrides = self: super: rec {
+  haskell-mode = self.melpaPackages.haskell-mode;
+  ...
+};
+((emacsPackagesGen emacs).overrideScope' overrides).emacsWithPackages (p: with p; [
+  # here both these package will use haskell-mode of our own choice
+  ghc-mod
+  dante
+])
+</screen>
+ </section>
+</section>

sources/nixpkgs/doc/builders/packages/ibus.xml

@@ -0,0 +1,57 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-ibus-typing-booster">
+ <title>ibus-engines.typing-booster</title>
+
+ <para>
+  This package is an ibus-based completion method to speed up typing.
+ </para>
+
+ <section xml:id="sec-ibus-typing-booster-activate">
+  <title>Activating the engine</title>
+
+  <para>
+   IBus needs to be configured accordingly to activate <literal>typing-booster</literal>. The configuration depends on the desktop manager in use. For detailed instructions, please refer to the <link xlink:href="https://mike-fabian.github.io/ibus-typing-booster/documentation.html">upstream docs</link>.
+  </para>
+
+  <para>
+   On NixOS you need to explicitly enable <literal>ibus</literal> with given engines before customizing your desktop to use <literal>typing-booster</literal>. This can be achieved using the <literal>ibus</literal> module:
+<programlisting>{ pkgs, ... }: {
+  i18n.inputMethod = {
+    enabled = "ibus";
+    ibus.engines = with pkgs.ibus-engines; [ typing-booster ];
+  };
+}</programlisting>
+  </para>
+ </section>
+
+ <section xml:id="sec-ibus-typing-booster-customize-hunspell">
+  <title>Using custom hunspell dictionaries</title>
+
+  <para>
+   The IBus engine is based on <literal>hunspell</literal> to support completion in many languages. By default the dictionaries <literal>de-de</literal>, <literal>en-us</literal>, <literal>fr-moderne</literal> <literal>es-es</literal>, <literal>it-it</literal>, <literal>sv-se</literal> and <literal>sv-fi</literal> are in use. To add another dictionary, the package can be overridden like this:
+<programlisting>ibus-engines.typing-booster.override {
+  langs = [ "de-at" "en-gb" ];
+}</programlisting>
+  </para>
+
+  <para>
+   <emphasis>Note: each language passed to <literal>langs</literal> must be an attribute name in <literal>pkgs.hunspellDicts</literal>.</emphasis>
+  </para>
+ </section>
+
+ <section xml:id="sec-ibus-typing-booster-emoji-picker">
+  <title>Built-in emoji picker</title>
+
+  <para>
+   The <literal>ibus-engines.typing-booster</literal> package contains a program named <literal>emoji-picker</literal>. To display all emojis correctly, a special font such as <literal>noto-fonts-emoji</literal> is needed:
+  </para>
+
+  <para>
+   On NixOS it can be installed using the following expression:
+<programlisting>{ pkgs, ... }: {
+  fonts.fonts = with pkgs; [ noto-fonts-emoji ];
+}</programlisting>
+  </para>
+ </section>
+</section>

sources/nixpkgs/doc/builders/packages/index.xml

@@ -0,0 +1,23 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="chap-packages">
+ <title>Packages</title>
+ <para>
+  This chapter contains information about how to use and maintain the Nix expressions for a number of specific packages, such as the Linux kernel or X.org.
+ </para>
+ <xi:include href="citrix.xml" />
+ <xi:include href="dlib.xml" />
+ <xi:include href="eclipse.xml" />
+ <xi:include href="elm.xml" />
+ <xi:include href="emacs.xml" />
+ <xi:include href="ibus.xml" />
+ <xi:include href="kakoune.xml" />
+ <xi:include href="linux.xml" />
+ <xi:include href="locales.xml" />
+ <xi:include href="nginx.xml" />
+ <xi:include href="opengl.xml" />
+ <xi:include href="shell-helpers.xml" />
+ <xi:include href="steam.xml" />
+ <xi:include href="weechat.xml" />
+ <xi:include href="xorg.xml" />
+</chapter>

sources/nixpkgs/doc/builders/packages/kakoune.xml

@@ -0,0 +1,14 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-kakoune">
+ <title>Kakoune</title>
+
+ <para>
+  Kakoune can be built to autoload plugins:
+<programlisting>(kakoune.override {
+  configure = {
+    plugins = with pkgs.kakounePlugins; [ parinfer-rust ];
+  };
+})</programlisting>
+ </para>
+</section>

sources/nixpkgs/doc/builders/packages/linux.xml

@@ -0,0 +1,85 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-linux-kernel">
+ <title>Linux kernel</title>
+
+ <para>
+  The Nix expressions to build the Linux kernel are in <link
+xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/os-specific/linux/kernel"><filename>pkgs/os-specific/linux/kernel</filename></link>.
+ </para>
+
+ <para>
+  The function that builds the kernel has an argument <varname>kernelPatches</varname> which should be a list of <literal>{name, patch, extraConfig}</literal> attribute sets, where <varname>name</varname> is the name of the patch (which is included in the kernel’s <varname>meta.description</varname> attribute), <varname>patch</varname> is the patch itself (possibly compressed), and <varname>extraConfig</varname> (optional) is a string specifying extra options to be concatenated to the kernel configuration file (<filename>.config</filename>).
+ </para>
+
+ <para>
+  The kernel derivation exports an attribute <varname>features</varname> specifying whether optional functionality is or isn’t enabled. This is used in NixOS to implement kernel-specific behaviour. For instance, if the kernel has the <varname>iwlwifi</varname> feature (i.e. has built-in support for Intel wireless chipsets), then NixOS doesn’t have to build the external <varname>iwlwifi</varname> package:
+<programlisting>
+modulesTree = [kernel]
+  ++ pkgs.lib.optional (!kernel.features ? iwlwifi) kernelPackages.iwlwifi
+  ++ ...;
+</programlisting>
+ </para>
+
+ <para>
+  How to add a new (major) version of the Linux kernel to Nixpkgs:
+  <orderedlist>
+   <listitem>
+    <para>
+     Copy the old Nix expression (e.g. <filename>linux-2.6.21.nix</filename>) to the new one (e.g. <filename>linux-2.6.22.nix</filename>) and update it.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Add the new kernel to <filename>all-packages.nix</filename> (e.g., create an attribute <varname>kernel_2_6_22</varname>).
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Now we’re going to update the kernel configuration. First unpack the kernel. Then for each supported platform (<literal>i686</literal>, <literal>x86_64</literal>, <literal>uml</literal>) do the following:
+     <orderedlist>
+      <listitem>
+       <para>
+        Make an copy from the old config (e.g. <filename>config-2.6.21-i686-smp</filename>) to the new one (e.g. <filename>config-2.6.22-i686-smp</filename>).
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Copy the config file for this platform (e.g. <filename>config-2.6.22-i686-smp</filename>) to <filename>.config</filename> in the kernel source tree.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Run <literal>make oldconfig ARCH=<replaceable>{i386,x86_64,um}</replaceable></literal> and answer all questions. (For the uml configuration, also add <literal>SHELL=bash</literal>.) Make sure to keep the configuration consistent between platforms (i.e. don’t enable some feature on <literal>i686</literal> and disable it on <literal>x86_64</literal>).
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        If needed you can also run <literal>make menuconfig</literal>:
+<screen>
+<prompt>$ </prompt>nix-env -i ncurses
+<prompt>$ </prompt>export NIX_CFLAGS_LINK=-lncurses
+<prompt>$ </prompt>make menuconfig ARCH=<replaceable>arch</replaceable></screen>
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Copy <filename>.config</filename> over the new config file (e.g. <filename>config-2.6.22-i686-smp</filename>).
+       </para>
+      </listitem>
+     </orderedlist>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Test building the kernel: <literal>nix-build -A kernel_2_6_22</literal>. If it compiles, ship it! For extra credit, try booting NixOS with it.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     It may be that the new kernel requires updating the external kernel modules and kernel-dependent packages listed in the <varname>linuxPackagesFor</varname> function in <filename>all-packages.nix</filename> (such as the NVIDIA drivers, AUFS, etc.). If the updated packages aren’t backwards compatible with older kernels, you may need to keep the older versions around.
+    </para>
+   </listitem>
+  </orderedlist>
+ </para>
+</section>

sources/nixpkgs/doc/builders/packages/locales.xml

@@ -0,0 +1,13 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="locales">
+ <title>Locales</title>
+
+ <para>
+  To allow simultaneous use of packages linked against different versions of <literal>glibc</literal> with different locale archive formats Nixpkgs patches <literal>glibc</literal> to rely on <literal>LOCALE_ARCHIVE</literal> environment variable.
+ </para>
+
+ <para>
+  On non-NixOS distributions this variable is obviously not set. This can cause regressions in language support or even crashes in some Nixpkgs-provided programs. The simplest way to mitigate this problem is exporting the <literal>LOCALE_ARCHIVE</literal> variable pointing to <literal>${glibcLocales}/lib/locale/locale-archive</literal>. The drawback (and the reason this is not the default) is the relatively large (a hundred MiB) size of the full set of locales. It is possible to build a custom set of locales by overriding parameters <literal>allLocales</literal> and <literal>locales</literal> of the package.
+ </para>
+</section>

sources/nixpkgs/doc/builders/packages/nginx.xml

@@ -0,0 +1,25 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-nginx">
+ <title>Nginx</title>
+
+ <para>
+  <link xlink:href="https://nginx.org/">Nginx</link> is a reverse proxy and lightweight webserver.
+ </para>
+
+ <section xml:id="sec-nginx-etag">
+  <title>ETags on static files served from the Nix store</title>
+
+  <para>
+   HTTP has a couple different mechanisms for caching to prevent clients from having to download the same content repeatedly if a resource has not changed since the last time it was requested. When nginx is used as a server for static files, it implements the caching mechanism based on the <link xlink:href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Last-Modified"><literal>Last-Modified</literal></link> response header automatically; unfortunately, it works by using filesystem timestamps to determine the value of the <literal>Last-Modified</literal> header. This doesn't give the desired behavior when the file is in the Nix store, because all file timestamps are set to 0 (for reasons related to build reproducibility).
+  </para>
+
+  <para>
+   Fortunately, HTTP supports an alternative (and more effective) caching mechanism: the <link xlink:href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag"><literal>ETag</literal></link> response header. The value of the <literal>ETag</literal> header specifies some identifier for the particular content that the server is sending (e.g. a hash). When a client makes a second request for the same resource, it sends that value back in an <literal>If-None-Match</literal> header. If the ETag value is unchanged, then the server does not need to resend the content.
+  </para>
+
+  <para>
+   As of NixOS 19.09, the nginx package in Nixpkgs is patched such that when nginx serves a file out of <filename>/nix/store</filename>, the hash in the store path is used as the <literal>ETag</literal> header in the HTTP response, thus providing proper caching functionality. This happens automatically; you do not need to do modify any configuration to get this behavior.
+  </para>
+ </section>
+</section>

sources/nixpkgs/doc/builders/packages/opengl.xml

@@ -0,0 +1,9 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-opengl">
+ <title>OpenGL</title>
+
+ <para>
+  Packages that use OpenGL have NixOS desktop as their primary target. The current solution for loading the GPU-specific drivers is based on <literal>libglvnd</literal> and looks for the driver implementation in <literal>LD_LIBRARY_PATH</literal>. If you are using a non-NixOS GNU/Linux/X11 desktop with free software video drivers, consider launching OpenGL-dependent programs from Nixpkgs with Nixpkgs versions of <literal>libglvnd</literal> and <literal>mesa_drivers</literal> in <literal>LD_LIBRARY_PATH</literal>. For proprietary video drivers you might have luck with also adding the corresponding video driver package.
+ </para>
+</section>

sources/nixpkgs/doc/builders/packages/shell-helpers.xml

@@ -0,0 +1,25 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-shell-helpers">
+ <title>Interactive shell helpers</title>
+
+ <para>
+  Some packages provide the shell integration to be more useful. But unlike other systems, nix doesn't have a standard share directory location. This is why a bunch <command>PACKAGE-share</command> scripts are shipped that print the location of the corresponding shared folder. Current list of such packages is as following:
+  <itemizedlist>
+   <listitem>
+    <para>
+     <literal>autojump</literal>: <command>autojump-share</command>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     <literal>fzf</literal>: <command>fzf-share</command>
+    </para>
+   </listitem>
+  </itemizedlist>
+  E.g. <literal>autojump</literal> can then used in the .bashrc like this:
+<screen>
+  source "$(autojump-share)/autojump.bash"
+</screen>
+ </para>
+</section>

sources/nixpkgs/doc/builders/packages/steam.xml

@@ -0,0 +1,131 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-steam">
+ <title>Steam</title>
+
+ <section xml:id="sec-steam-nix">
+  <title>Steam in Nix</title>
+
+  <para>
+   Steam is distributed as a <filename>.deb</filename> file, for now only as an i686 package (the amd64 package only has documentation). When unpacked, it has a script called <filename>steam</filename> that in Ubuntu (their target distro) would go to <filename>/usr/bin </filename>. When run for the first time, this script copies some files to the user's home, which include another script that is the ultimate responsible for launching the steam binary, which is also in $HOME.
+  </para>
+
+  <para>
+   Nix problems and constraints:
+   <itemizedlist>
+    <listitem>
+     <para>
+      We don't have <filename>/bin/bash</filename> and many scripts point there. Similarly for <filename>/usr/bin/python</filename> .
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      We don't have the dynamic loader in <filename>/lib </filename>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The <filename>steam.sh</filename> script in $HOME can not be patched, as it is checked and rewritten by steam.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The steam binary cannot be patched, it's also checked.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+
+  <para>
+   The current approach to deploy Steam in NixOS is composing a FHS-compatible chroot environment, as documented <link xlink:href="http://sandervanderburg.blogspot.nl/2013/09/composing-fhs-compatible-chroot.html">here</link>. This allows us to have binaries in the expected paths without disrupting the system, and to avoid patching them to work in a non FHS environment.
+  </para>
+ </section>
+
+ <section xml:id="sec-steam-play">
+  <title>How to play</title>
+
+  <para>
+   For 64-bit systems it's important to have
+<programlisting>hardware.opengl.driSupport32Bit = true;</programlisting>
+   in your <filename>/etc/nixos/configuration.nix</filename>. You'll also need
+<programlisting>hardware.pulseaudio.support32Bit = true;</programlisting>
+   if you are using PulseAudio - this will enable 32bit ALSA apps integration. To use the Steam controller or other Steam supported controllers such as the DualShock 4 or Nintendo Switch Pro, you need to add
+<programlisting>hardware.steam-hardware.enable = true;</programlisting>
+   to your configuration.
+  </para>
+ </section>
+
+ <section xml:id="sec-steam-troub">
+  <title>Troubleshooting</title>
+
+  <para>
+   <variablelist>
+    <varlistentry>
+     <term>
+      Steam fails to start. What do I do?
+     </term>
+     <listitem>
+      <para>
+       Try to run
+<programlisting>strace steam</programlisting>
+       to see what is causing steam to fail.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      Using the FOSS Radeon or nouveau (nvidia) drivers
+     </term>
+     <listitem>
+      <itemizedlist>
+       <listitem>
+        <para>
+         The <literal>newStdcpp</literal> parameter was removed since NixOS 17.09 and should not be needed anymore.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Steam ships statically linked with a version of libcrypto that conflics with the one dynamically loaded by radeonsi_dri.so. If you get the error
+<programlisting>steam.sh: line 713: 7842 Segmentation fault (core dumped)</programlisting>
+         have a look at <link xlink:href="https://github.com/NixOS/nixpkgs/pull/20269">this pull request</link>.
+        </para>
+       </listitem>
+      </itemizedlist>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      Java
+     </term>
+     <listitem>
+      <orderedlist>
+       <listitem>
+        <para>
+         There is no java in steam chrootenv by default. If you get a message like
+<programlisting>/home/foo/.local/share/Steam/SteamApps/common/towns/towns.sh: line 1: java: command not found</programlisting>
+         You need to add
+<programlisting> steam.override { withJava = true; };</programlisting>
+         to your configuration.
+        </para>
+       </listitem>
+      </orderedlist>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </para>
+ </section>
+
+ <section xml:id="sec-steam-run">
+  <title>steam-run</title>
+
+  <para>
+   The FHS-compatible chroot used for steam can also be used to run other linux games that expect a FHS environment. To do it, add
+<programlisting>pkgs.(steam.override {
+          nativeOnly = true;
+          newStdcpp = true;
+        }).run</programlisting>
+   to your configuration, rebuild, and run the game with
+<programlisting>steam-run ./foo</programlisting>
+  </para>
+ </section>
+</section>

sources/nixpkgs/doc/builders/packages/unfree.xml

@@ -0,0 +1,13 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="unfree-software">
+ <title>Unfree software</title>
+
+ <para>
+  All users of Nixpkgs are free software users, and many users (and developers) of Nixpkgs want to limit and tightly control their exposure to unfree software. At the same time, many users need (or want) to run some specific pieces of proprietary software. Nixpkgs includes some expressions for unfree software packages. By default unfree software cannot be installed and doesn’t show up in searches. To allow installing unfree software in a single Nix invocation one can export <literal>NIXPKGS_ALLOW_UNFREE=1</literal>. For a persistent solution, users can set <literal>allowUnfree</literal> in the Nixpkgs configuration.
+ </para>
+
+ <para>
+  Fine-grained control is possible by defining <literal>allowUnfreePredicate</literal> function in config; it takes the <literal>mkDerivation</literal> parameter attrset and returns <literal>true</literal> for unfree packages that should be allowed.
+ </para>
+</section>

sources/nixpkgs/doc/builders/packages/weechat.xml

@@ -0,0 +1,85 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-weechat">
+ <title>Weechat</title>
+
+ <para>
+  Weechat can be configured to include your choice of plugins, reducing its closure size from the default configuration which includes all available plugins. To make use of this functionality, install an expression that overrides its configuration such as
+<programlisting>weechat.override {configure = {availablePlugins, ...}: {
+    plugins = with availablePlugins; [ python perl ];
+  }
+}</programlisting>
+  If the <literal>configure</literal> function returns an attrset without the <literal>plugins</literal> attribute, <literal>availablePlugins</literal> will be used automatically.
+ </para>
+
+ <para>
+  The plugins currently available are <literal>python</literal>, <literal>perl</literal>, <literal>ruby</literal>, <literal>guile</literal>, <literal>tcl</literal> and <literal>lua</literal>.
+ </para>
+
+ <para>
+  The python and perl plugins allows the addition of extra libraries. For instance, the <literal>inotify.py</literal> script in weechat-scripts requires D-Bus or libnotify, and the <literal>fish.py</literal> script requires pycrypto. To use these scripts, use the plugin's <literal>withPackages</literal> attribute:
+<programlisting>weechat.override { configure = {availablePlugins, ...}: {
+    plugins = with availablePlugins; [
+            (python.withPackages (ps: with ps; [ pycrypto python-dbus ]))
+        ];
+    };
+}
+</programlisting>
+ </para>
+
+ <para>
+  In order to also keep all default plugins installed, it is possible to use the following method:
+<programlisting>weechat.override { configure = { availablePlugins, ... }: {
+  plugins = builtins.attrValues (availablePlugins // {
+    python = availablePlugins.python.withPackages (ps: with ps; [ pycrypto python-dbus ]);
+  });
+}; }
+</programlisting>
+ </para>
+
+ <para>
+  WeeChat allows to set defaults on startup using the <literal>--run-command</literal>. The <literal>configure</literal> method can be used to pass commands to the program:
+<programlisting>weechat.override {
+  configure = { availablePlugins, ... }: {
+    init = ''
+      /set foo bar
+      /server add freenode chat.freenode.org
+    '';
+  };
+}</programlisting>
+  Further values can be added to the list of commands when running <literal>weechat --run-command "your-commands"</literal>.
+ </para>
+
+ <para>
+  Additionally it's possible to specify scripts to be loaded when starting <literal>weechat</literal>. These will be loaded before the commands from <literal>init</literal>:
+<programlisting>weechat.override {
+  configure = { availablePlugins, ... }: {
+    scripts = with pkgs.weechatScripts; [
+      weechat-xmpp weechat-matrix-bridge wee-slack
+    ];
+    init = ''
+      /set plugins.var.python.jabber.key "val"
+    '':
+  };
+}</programlisting>
+ </para>
+
+ <para>
+  In <literal>nixpkgs</literal> there's a subpackage which contains derivations for WeeChat scripts. Such derivations expect a <literal>passthru.scripts</literal> attribute which contains a list of all scripts inside the store path. Furthermore all scripts have to live in <literal>$out/share</literal>. An exemplary derivation looks like this:
+<programlisting>{ stdenv, fetchurl }:
+
+stdenv.mkDerivation {
+  name = "exemplary-weechat-script";
+  src = fetchurl {
+    url = "https://scripts.tld/your-scripts.tar.gz";
+    sha256 = "...";
+  };
+  passthru.scripts = [ "foo.py" "bar.lua" ];
+  installPhase = ''
+    mkdir $out/share
+    cp foo.py $out/share
+    cp bar.lua $out/share
+  '';
+}</programlisting>
+ </para>
+</section>

sources/nixpkgs/doc/builders/packages/xorg.xml

@@ -0,0 +1,34 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-xorg">
+ <title>X.org</title>
+
+ <para>
+  The Nix expressions for the X.org packages reside in <filename>pkgs/servers/x11/xorg/default.nix</filename>. This file is automatically generated from lists of tarballs in an X.org release. As such it should not be modified directly; rather, you should modify the lists, the generator script or the file <filename>pkgs/servers/x11/xorg/overrides.nix</filename>, in which you can override or add to the derivations produced by the generator.
+ </para>
+
+ <para>
+  The generator is invoked as follows:
+<screen>
+<prompt>$ </prompt>cd pkgs/servers/x11/xorg
+<prompt>$ </prompt>cat tarballs-7.5.list extra.list old.list \
+  | perl ./generate-expr-from-tarballs.pl
+</screen>
+  For each of the tarballs in the <filename>.list</filename> files, the script downloads it, unpacks it, and searches its <filename>configure.ac</filename> and <filename>*.pc.in</filename> files for dependencies. This information is used to generate <filename>default.nix</filename>. The generator caches downloaded tarballs between runs. Pay close attention to the <literal>NOT FOUND: <replaceable>name</replaceable></literal> messages at the end of the run, since they may indicate missing dependencies. (Some might be optional dependencies, however.)
+ </para>
+
+ <para>
+  A file like <filename>tarballs-7.5.list</filename> contains all tarballs in a X.org release. It can be generated like this:
+<screen>
+<prompt>$ </prompt>export i="mirror://xorg/X11R7.4/src/everything/"
+<prompt>$ </prompt>cat $(PRINT_PATH=1 nix-prefetch-url $i | tail -n 1) \
+  | perl -e 'while (&lt;>) { if (/(href|HREF)="([^"]*.bz2)"/) { print "$ENV{'i'}$2\n"; }; }' \
+  | sort > tarballs-7.4.list
+</screen>
+  <filename>extra.list</filename> contains libraries that aren’t part of X.org proper, but are closely related to it, such as <literal>libxcb</literal>. <filename>old.list</filename> contains some packages that were removed from X.org, but are still needed by some people or by other packages (such as <varname>imake</varname>).
+ </para>
+
+ <para>
+  If the expression for a package requires derivation attributes that the generator cannot figure out automatically (say, <varname>patches</varname> or a <varname>postInstall</varname> hook), you should modify <filename>pkgs/servers/x11/xorg/overrides.nix</filename>.
+ </para>
+</section>

sources/nixpkgs/doc/builders/special.xml

@@ -0,0 +1,10 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="chap-special">
+ <title>Special builders</title>
+ <para>
+  This chapter describes several special builders.
+ </para>
+ <xi:include href="special/fhs-environments.xml" />
+ <xi:include href="special/mkshell.xml" />
+</chapter>

sources/nixpkgs/doc/builders/special/fhs-environments.xml

@@ -0,0 +1,122 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-fhs-environments">
+ <title>buildFHSUserEnv</title>
+
+ <para>
+  <function>buildFHSUserEnv</function> provides a way to build and run FHS-compatible lightweight sandboxes. It creates an isolated root with bound <filename>/nix/store</filename>, so its footprint in terms of disk space needed is quite small. This allows one to run software which is hard or unfeasible to patch for NixOS -- 3rd-party source trees with FHS assumptions, games distributed as tarballs, software with integrity checking and/or external self-updated binaries. It uses Linux namespaces feature to create temporary lightweight environments which are destroyed after all child processes exit, without root user rights requirement. Accepted arguments are:
+ </para>
+
+ <variablelist>
+  <varlistentry>
+   <term>
+    <literal>name</literal>
+   </term>
+   <listitem>
+    <para>
+     Environment name.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>targetPkgs</literal>
+   </term>
+   <listitem>
+    <para>
+     Packages to be installed for the main host's architecture (i.e. x86_64 on x86_64 installations). Along with libraries binaries are also installed.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>multiPkgs</literal>
+   </term>
+   <listitem>
+    <para>
+     Packages to be installed for all architectures supported by a host (i.e. i686 and x86_64 on x86_64 installations). Only libraries are installed by default.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>extraBuildCommands</literal>
+   </term>
+   <listitem>
+    <para>
+     Additional commands to be executed for finalizing the directory structure.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>extraBuildCommandsMulti</literal>
+   </term>
+   <listitem>
+    <para>
+     Like <literal>extraBuildCommands</literal>, but executed only on multilib architectures.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>extraOutputsToInstall</literal>
+   </term>
+   <listitem>
+    <para>
+     Additional derivation outputs to be linked for both target and multi-architecture packages.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>extraInstallCommands</literal>
+   </term>
+   <listitem>
+    <para>
+     Additional commands to be executed for finalizing the derivation with runner script.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>runScript</literal>
+   </term>
+   <listitem>
+    <para>
+     A command that would be executed inside the sandbox and passed all the command line arguments. It defaults to <literal>bash</literal>.
+    </para>
+   </listitem>
+  </varlistentry>
+ </variablelist>
+
+ <para>
+  One can create a simple environment using a <literal>shell.nix</literal> like that:
+ </para>
+
+<programlisting><![CDATA[
+{ pkgs ? import <nixpkgs> {} }:
+
+(pkgs.buildFHSUserEnv {
+  name = "simple-x11-env";
+  targetPkgs = pkgs: (with pkgs;
+    [ udev
+      alsaLib
+    ]) ++ (with pkgs.xorg;
+    [ libX11
+      libXcursor
+      libXrandr
+    ]);
+  multiPkgs = pkgs: (with pkgs;
+    [ udev
+      alsaLib
+    ]);
+  runScript = "bash";
+}).env
+]]></programlisting>
+
+ <para>
+  Running <literal>nix-shell</literal> would then drop you into a shell with these libraries and binaries available. You can use this to run closed-source applications which expect FHS structure without hassles: simply change <literal>runScript</literal> to the application path, e.g. <filename>./bin/start.sh</filename> -- relative paths are supported.
+ </para>
+</section>

sources/nixpkgs/doc/builders/special/mkshell.xml

@@ -0,0 +1,24 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-pkgs-mkShell">
+ <title>pkgs.mkShell</title>
+
+ <para>
+  <function>pkgs.mkShell</function> is a special kind of derivation that is only useful when using it combined with <command>nix-shell</command>. It will in fact fail to instantiate when invoked with <command>nix-build</command>.
+ </para>
+
+ <section xml:id="sec-pkgs-mkShell-usage">
+  <title>Usage</title>
+
+<programlisting><![CDATA[
+{ pkgs ? import <nixpkgs> {} }:
+pkgs.mkShell {
+  # this will make all the build inputs from hello and gnutar
+  # available to the shell environment
+  inputsFrom = with pkgs; [ hello gnutar ];
+  buildInputs = [ pkgs.gnumake ];
+}
+]]></programlisting>
+ </section>
+</section>

sources/nixpkgs/doc/builders/trivial-builders.xml

@@ -0,0 +1,90 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="chap-trivial-builders">
+ <title>Trivial builders</title>
+ <para>
+  Nixpkgs provides a couple of functions that help with building derivations. The most important one, <function>stdenv.mkDerivation</function>, has already been documented above. The following functions wrap <function>stdenv.mkDerivation</function>, making it easier to use in certain cases.
+ </para>
+ <variablelist>
+  <varlistentry xml:id="trivial-builder-runCommand">
+   <term>
+    <literal>runCommand</literal>
+   </term>
+   <listitem>
+    <para>
+     This takes three arguments, <literal>name</literal>, <literal>env</literal>, and <literal>buildCommand</literal>. <literal>name</literal> is just the name that Nix will append to the store path in the same way that <literal>stdenv.mkDerivation</literal> uses its <literal>name</literal> attribute. <literal>env</literal> is an attribute set specifying environment variables that will be set for this derivation. These attributes are then passed to the wrapped <literal>stdenv.mkDerivation</literal>. <literal>buildCommand</literal> specifies the commands that will be run to create this derivation. Note that you will need to create <literal>$out</literal> for Nix to register the command as successful.
+    </para>
+    <para>
+     An example of using <literal>runCommand</literal> is provided below.
+    </para>
+<programlisting>
+(import &lt;nixpkgs&gt; {}).runCommand "my-example" {} ''
+  echo My example command is running
+
+  mkdir $out
+
+  echo I can write data to the Nix store > $out/message
+
+  echo I can also run basic commands like:
+
+  echo ls
+  ls
+
+  echo whoami
+  whoami
+
+  echo date
+  date
+''
+</programlisting>
+   </listitem>
+  </varlistentry>
+  <varlistentry xml:id="trivial-builder-runCommandCC">
+   <term>
+    <literal>runCommandCC</literal>
+   </term>
+   <listitem>
+    <para>
+     This works just like <literal>runCommand</literal>. The only difference is that it also provides a C compiler in <literal>buildCommand</literal>’s environment. To minimize your dependencies, you should only use this if you are sure you will need a C compiler as part of running your command.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry xml:id="trivial-builder-runCommandLocal">
+   <term>
+    <literal>runCommandLocal</literal>
+   </term>
+   <listitem>
+    <para>
+     Variant of <literal>runCommand</literal> that forces the derivation to be built locally, it is not substituted. This is intended for very cheap commands (&lt;1s execution time). It saves on the network roundrip and can speed up a build.
+    </para>
+    <note><para>
+      This sets <link xlink:href="https://nixos.org/nix/manual/#adv-attr-allowSubstitutes"><literal>allowSubstitutes</literal> to <literal>false</literal></link>, so only use <literal>runCommandLocal</literal> if you are certain the user will always have a builder for the <literal>system</literal> of the derivation. This should be true for most trivial use cases (e.g. just copying some files to a different location or adding symlinks), because there the <literal>system</literal> is usually the same as <literal>builtins.currentSystem</literal>.
+    </para></note>
+   </listitem>
+  </varlistentry>
+  <varlistentry xml:id="trivial-builder-writeText">
+   <term>
+    <literal>writeTextFile</literal>, <literal>writeText</literal>, <literal>writeTextDir</literal>, <literal>writeScript</literal>, <literal>writeScriptBin</literal>
+   </term>
+   <listitem>
+    <para>
+     These functions write <literal>text</literal> to the Nix store. This is useful for creating scripts from Nix expressions. <literal>writeTextFile</literal> takes an attribute set and expects two arguments, <literal>name</literal> and <literal>text</literal>. <literal>name</literal> corresponds to the name used in the Nix store path. <literal>text</literal> will be the contents of the file. You can also set <literal>executable</literal> to true to make this file have the executable bit set.
+    </para>
+    <para>
+     Many more commands wrap <literal>writeTextFile</literal> including <literal>writeText</literal>, <literal>writeTextDir</literal>, <literal>writeScript</literal>, and <literal>writeScriptBin</literal>. These are convenience functions over <literal>writeTextFile</literal>.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry xml:id="trivial-builder-symlinkJoin">
+   <term>
+    <literal>symlinkJoin</literal>
+   </term>
+   <listitem>
+    <para>
+     This can be used to put many derivations into the same directory structure. It works by creating a new derivation and adding symlinks to each of the paths listed. It expects two arguments, <literal>name</literal>, and <literal>paths</literal>. <literal>name</literal> is the name used in the Nix store path for the created derivation. <literal>paths</literal> is a list of paths that will be symlinked. These paths can be to Nix store derivations or any other subdirectory contained within.
+    </para>
+   </listitem>
+  </varlistentry>
+ </variablelist>
+</chapter>

sources/nixpkgs/doc/contributing/coding-conventions.xml

@@ -0,0 +1,924 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-conventions">
+ <title>Coding conventions</title>
+ <section xml:id="sec-syntax">
+  <title>Syntax</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Use 2 spaces of indentation per indentation level in Nix expressions, 4 spaces in shell scripts.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Do not use tab characters, i.e. configure your editor to use soft tabs. For instance, use <literal>(setq-default indent-tabs-mode nil)</literal> in Emacs. Everybody has different tab settings so it’s asking for trouble.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Use <literal>lowerCamelCase</literal> for variable names, not <literal>UpperCamelCase</literal>. Note, this rule does not apply to package attribute names, which instead follow the rules in <xref linkend="sec-package-naming"/>.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Function calls with attribute set arguments are written as
+<programlisting>
+foo {
+  arg = ...;
+}
+</programlisting>
+     not
+<programlisting>
+foo
+{
+  arg = ...;
+}
+</programlisting>
+     Also fine is
+<programlisting>
+foo { arg = ...; }
+</programlisting>
+     if it's a short call.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     In attribute sets or lists that span multiple lines, the attribute names or list elements should be aligned:
+<programlisting>
+# A long list.
+list = [
+  elem1
+  elem2
+  elem3
+];
+
+# A long attribute set.
+attrs = {
+  attr1 = short_expr;
+  attr2 =
+    if true then big_expr else big_expr;
+};
+
+# Combined
+listOfAttrs = [
+  {
+    attr1 = 3;
+    attr2 = "fff";
+  }
+  {
+    attr1 = 5;
+    attr2 = "ggg";
+  }
+];
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Short lists or attribute sets can be written on one line:
+<programlisting>
+# A short list.
+list = [ elem1 elem2 elem3 ];
+
+# A short set.
+attrs = { x = 1280; y = 1024; };
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Breaking in the middle of a function argument can give hard-to-read code, like
+<programlisting>
+someFunction { x = 1280;
+  y = 1024; } otherArg
+  yetAnotherArg
+</programlisting>
+     (especially if the argument is very large, spanning multiple lines).
+    </para>
+    <para>
+     Better:
+<programlisting>
+someFunction
+  { x = 1280; y = 1024; }
+  otherArg
+  yetAnotherArg
+</programlisting>
+     or
+<programlisting>
+let res = { x = 1280; y = 1024; };
+in someFunction res otherArg yetAnotherArg
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     The bodies of functions, asserts, and withs are not indented to prevent a lot of superfluous indentation levels, i.e.
+<programlisting>
+{ arg1, arg2 }:
+assert system == "i686-linux";
+stdenv.mkDerivation { ...
+</programlisting>
+     not
+<programlisting>
+{ arg1, arg2 }:
+  assert system == "i686-linux";
+    stdenv.mkDerivation { ...
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Function formal arguments are written as:
+<programlisting>
+{ arg1, arg2, arg3 }:
+</programlisting>
+     but if they don't fit on one line they're written as:
+<programlisting>
+{ arg1, arg2, arg3
+, arg4, ...
+, # Some comment...
+  argN
+}:
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Functions should list their expected arguments as precisely as possible. That is, write
+<programlisting>
+{ stdenv, fetchurl, perl }: <replaceable>...</replaceable>
+</programlisting>
+     instead of
+<programlisting>
+args: with args; <replaceable>...</replaceable>
+</programlisting>
+     or
+<programlisting>
+{ stdenv, fetchurl, perl, ... }: <replaceable>...</replaceable>
+</programlisting>
+    </para>
+    <para>
+     For functions that are truly generic in the number of arguments (such as wrappers around <varname>mkDerivation</varname>) that have some required arguments, you should write them using an <literal>@</literal>-pattern:
+<programlisting>
+{ stdenv, doCoverageAnalysis ? false, ... } @ args:
+
+stdenv.mkDerivation (args // {
+  <replaceable>...</replaceable> if doCoverageAnalysis then "bla" else "" <replaceable>...</replaceable>
+})
+</programlisting>
+     instead of
+<programlisting>
+args:
+
+args.stdenv.mkDerivation (args // {
+  <replaceable>...</replaceable> if args ? doCoverageAnalysis &amp;&amp; args.doCoverageAnalysis then "bla" else "" <replaceable>...</replaceable>
+})
+</programlisting>
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+ <section xml:id="sec-package-naming">
+  <title>Package naming</title>
+
+  <para>
+   The key words <emphasis>must</emphasis>, <emphasis>must not</emphasis>, <emphasis>required</emphasis>, <emphasis>shall</emphasis>, <emphasis>shall not</emphasis>, <emphasis>should</emphasis>, <emphasis>should not</emphasis>, <emphasis>recommended</emphasis>, <emphasis>may</emphasis>, and <emphasis>optional</emphasis> in this section are to be interpreted as described in <link xlink:href="https://tools.ietf.org/html/rfc2119">RFC 2119</link>. Only <emphasis>emphasized</emphasis> words are to be interpreted in this way.
+  </para>
+
+  <para>
+   In Nixpkgs, there are generally three different names associated with a package:
+   <itemizedlist>
+    <listitem>
+     <para>
+      The <varname>name</varname> attribute of the derivation (excluding the version part). This is what most users see, in particular when using <command>nix-env</command>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The variable name used for the instantiated package in <filename>all-packages.nix</filename>, and when passing it as a dependency to other functions. Typically this is called the <emphasis>package attribute name</emphasis>. This is what Nix expression authors see. It can also be used when installing using <command>nix-env -iA</command>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The filename for (the directory containing) the Nix expression.
+     </para>
+    </listitem>
+   </itemizedlist>
+   Most of the time, these are the same. For instance, the package <literal>e2fsprogs</literal> has a <varname>name</varname> attribute <literal>"e2fsprogs-<replaceable>version</replaceable>"</literal>, is bound to the variable name <varname>e2fsprogs</varname> in <filename>all-packages.nix</filename>, and the Nix expression is in <filename>pkgs/os-specific/linux/e2fsprogs/default.nix</filename>.
+  </para>
+
+  <para>
+   There are a few naming guidelines:
+   <itemizedlist>
+    <listitem>
+     <para>
+      The <literal>name</literal> attribute <emphasis>should</emphasis> be identical to the upstream package name.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The <literal>name</literal> attribute <emphasis>must not</emphasis> contain uppercase letters — e.g., <literal>"mplayer-1.0rc2"</literal> instead of <literal>"MPlayer-1.0rc2"</literal>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The version part of the <literal>name</literal> attribute <emphasis>must</emphasis> start with a digit (following a dash) — e.g., <literal>"hello-0.3.1rc2"</literal>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      If a package is not a release but a commit from a repository, then the version part of the name <emphasis>must</emphasis> be the date of that (fetched) commit. The date <emphasis>must</emphasis> be in <literal>"YYYY-MM-DD"</literal> format. Also append <literal>"unstable"</literal> to the name - e.g., <literal>"pkgname-unstable-2014-09-23"</literal>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Dashes in the package name <emphasis>should</emphasis> be preserved in new variable names, rather than converted to underscores or camel cased — e.g., <varname>http-parser</varname> instead of <varname>http_parser</varname> or <varname>httpParser</varname>. The hyphenated style is preferred in all three package names.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      If there are multiple versions of a package, this <emphasis>should</emphasis> be reflected in the variable names in <filename>all-packages.nix</filename>, e.g. <varname>json-c-0-9</varname> and <varname>json-c-0-11</varname>. If there is an obvious “default” version, make an attribute like <literal>json-c = json-c-0-9;</literal>. See also <xref linkend="sec-versioning" />
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+ </section>
+ <section xml:id="sec-organisation">
+  <title>File naming and organisation</title>
+
+  <para>
+   Names of files and directories should be in lowercase, with dashes between words — not in camel case. For instance, it should be <filename>all-packages.nix</filename>, not <filename>allPackages.nix</filename> or <filename>AllPackages.nix</filename>.
+  </para>
+
+  <section xml:id="sec-hierarchy">
+   <title>Hierarchy</title>
+
+   <para>
+    Each package should be stored in its own directory somewhere in the <filename>pkgs/</filename> tree, i.e. in <filename>pkgs/<replaceable>category</replaceable>/<replaceable>subcategory</replaceable>/<replaceable>...</replaceable>/<replaceable>pkgname</replaceable></filename>. Below are some rules for picking the right category for a package. Many packages fall under several categories; what matters is the <emphasis>primary</emphasis> purpose of a package. For example, the <literal>libxml2</literal> package builds both a library and some tools; but it’s a library foremost, so it goes under <filename>pkgs/development/libraries</filename>.
+   </para>
+
+   <para>
+    When in doubt, consider refactoring the <filename>pkgs/</filename> tree, e.g. creating new categories or splitting up an existing category.
+   </para>
+
+   <variablelist>
+    <varlistentry>
+     <term>
+      If it’s used to support <emphasis>software development</emphasis>:
+     </term>
+     <listitem>
+      <variablelist>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>library</emphasis> used by other packages:
+        </term>
+        <listitem>
+         <para>
+          <filename>development/libraries</filename> (e.g. <filename>libxml2</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>compiler</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>development/compilers</filename> (e.g. <filename>gcc</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s an <emphasis>interpreter</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>development/interpreters</filename> (e.g. <filename>guile</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s a (set of) development <emphasis>tool(s)</emphasis>:
+        </term>
+        <listitem>
+         <variablelist>
+          <varlistentry>
+           <term>
+            If it’s a <emphasis>parser generator</emphasis> (including lexers):
+           </term>
+           <listitem>
+            <para>
+             <filename>development/tools/parsing</filename> (e.g. <filename>bison</filename>, <filename>flex</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            If it’s a <emphasis>build manager</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             <filename>development/tools/build-managers</filename> (e.g. <filename>gnumake</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            Else:
+           </term>
+           <listitem>
+            <para>
+             <filename>development/tools/misc</filename> (e.g. <filename>binutils</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+         </variablelist>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         Else:
+        </term>
+        <listitem>
+         <para>
+          <filename>development/misc</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+      </variablelist>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a (set of) <emphasis>tool(s)</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       (A tool is a relatively small program, especially one intended to be used non-interactively.)
+      </para>
+      <variablelist>
+       <varlistentry>
+        <term>
+         If it’s for <emphasis>networking</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/networking</filename> (e.g. <filename>wget</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s for <emphasis>text processing</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/text</filename> (e.g. <filename>diffutils</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>system utility</emphasis>, i.e., something related or essential to the operation of a system:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/system</filename> (e.g. <filename>cron</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s an <emphasis>archiver</emphasis> (which may include a compression function):
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/archivers</filename> (e.g. <filename>zip</filename>, <filename>tar</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>compression</emphasis> program:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/compression</filename> (e.g. <filename>gzip</filename>, <filename>bzip2</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>security</emphasis>-related program:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/security</filename> (e.g. <filename>nmap</filename>, <filename>gnupg</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         Else:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/misc</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+      </variablelist>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a <emphasis>shell</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       <filename>shells</filename> (e.g. <filename>bash</filename>)
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a <emphasis>server</emphasis>:
+     </term>
+     <listitem>
+      <variablelist>
+       <varlistentry>
+        <term>
+         If it’s a web server:
+        </term>
+        <listitem>
+         <para>
+          <filename>servers/http</filename> (e.g. <filename>apache-httpd</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s an implementation of the X Windowing System:
+        </term>
+        <listitem>
+         <para>
+          <filename>servers/x11</filename> (e.g. <filename>xorg</filename> — this includes the client libraries and programs)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         Else:
+        </term>
+        <listitem>
+         <para>
+          <filename>servers/misc</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+      </variablelist>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a <emphasis>desktop environment</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       <filename>desktops</filename> (e.g. <filename>kde</filename>, <filename>gnome</filename>, <filename>enlightenment</filename>)
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a <emphasis>window manager</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       <filename>applications/window-managers</filename> (e.g. <filename>awesome</filename>, <filename>stumpwm</filename>)
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s an <emphasis>application</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       A (typically large) program with a distinct user interface, primarily used interactively.
+      </para>
+      <variablelist>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>version management system</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>applications/version-management</filename> (e.g. <filename>subversion</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s for <emphasis>video playback / editing</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>applications/video</filename> (e.g. <filename>vlc</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s for <emphasis>graphics viewing / editing</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>applications/graphics</filename> (e.g. <filename>gimp</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s for <emphasis>networking</emphasis>:
+        </term>
+        <listitem>
+         <variablelist>
+          <varlistentry>
+           <term>
+            If it’s a <emphasis>mailreader</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             <filename>applications/networking/mailreaders</filename> (e.g. <filename>thunderbird</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            If it’s a <emphasis>newsreader</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             <filename>applications/networking/newsreaders</filename> (e.g. <filename>pan</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            If it’s a <emphasis>web browser</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             <filename>applications/networking/browsers</filename> (e.g. <filename>firefox</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            Else:
+           </term>
+           <listitem>
+            <para>
+             <filename>applications/networking/misc</filename>
+            </para>
+           </listitem>
+          </varlistentry>
+         </variablelist>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         Else:
+        </term>
+        <listitem>
+         <para>
+          <filename>applications/misc</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+      </variablelist>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s <emphasis>data</emphasis> (i.e., does not have a straight-forward executable semantics):
+     </term>
+     <listitem>
+      <variablelist>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>font</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>data/fonts</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s an <emphasis>icon theme</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>data/icons</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s related to <emphasis>SGML/XML processing</emphasis>:
+        </term>
+        <listitem>
+         <variablelist>
+          <varlistentry>
+           <term>
+            If it’s an <emphasis>XML DTD</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             <filename>data/sgml+xml/schemas/xml-dtd</filename> (e.g. <filename>docbook</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            If it’s an <emphasis>XSLT stylesheet</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             (Okay, these are executable...)
+            </para>
+            <para>
+             <filename>data/sgml+xml/stylesheets/xslt</filename> (e.g. <filename>docbook-xsl</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+         </variablelist>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>theme</emphasis> for a <emphasis>desktop environment</emphasis>,
+         a <emphasis>window manager</emphasis> or a <emphasis>display manager</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>data/themes</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+      </variablelist>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a <emphasis>game</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       <filename>games</filename>
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      Else:
+     </term>
+     <listitem>
+      <para>
+       <filename>misc</filename>
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+
+  <section xml:id="sec-versioning">
+   <title>Versioning</title>
+
+   <para>
+    Because every version of a package in Nixpkgs creates a potential maintenance burden, old versions of a package should not be kept unless there is a good reason to do so. For instance, Nixpkgs contains several versions of GCC because other packages don’t build with the latest version of GCC. Other examples are having both the latest stable and latest pre-release version of a package, or to keep several major releases of an application that differ significantly in functionality.
+   </para>
+
+   <para>
+    If there is only one version of a package, its Nix expression should be named <filename>e2fsprogs/default.nix</filename>. If there are multiple versions, this should be reflected in the filename, e.g. <filename>e2fsprogs/1.41.8.nix</filename> and <filename>e2fsprogs/1.41.9.nix</filename>. The version in the filename should leave out unnecessary detail. For instance, if we keep the latest Firefox 2.0.x and 3.5.x versions in Nixpkgs, they should be named <filename>firefox/2.0.nix</filename> and <filename>firefox/3.5.nix</filename>, respectively (which, at a given point, might contain versions <literal>2.0.0.20</literal> and <literal>3.5.4</literal>). If a version requires many auxiliary files, you can use a subdirectory for each version, e.g. <filename>firefox/2.0/default.nix</filename> and <filename>firefox/3.5/default.nix</filename>.
+   </para>
+
+   <para>
+    All versions of a package <emphasis>must</emphasis> be included in <filename>all-packages.nix</filename> to make sure that they evaluate correctly.
+   </para>
+  </section>
+ </section>
+ <section xml:id="sec-sources">
+  <title>Fetching Sources</title>
+
+  <para>
+   There are multiple ways to fetch a package source in nixpkgs. The general guideline is that you should package reproducible sources with a high degree of availability. Right now there is only one fetcher which has mirroring support and that is <literal>fetchurl</literal>. Note that you should also prefer protocols which have a corresponding proxy environment variable.
+  </para>
+
+  <para>
+   You can find many source fetch helpers in <literal>pkgs/build-support/fetch*</literal>.
+  </para>
+
+  <para>
+   In the file <literal>pkgs/top-level/all-packages.nix</literal> you can find fetch helpers, these have names on the form <literal>fetchFrom*</literal>. The intention of these are to provide snapshot fetches but using the same api as some of the version controlled fetchers from <literal>pkgs/build-support/</literal>. As an example going from bad to good:
+   <itemizedlist>
+    <listitem>
+     <para>
+      Bad: Uses <literal>git://</literal> which won't be proxied.
+<programlisting>
+src = fetchgit {
+  url = "git://github.com/NixOS/nix.git";
+  rev = "1f795f9f44607cc5bec70d1300150bfefcef2aae";
+  sha256 = "1cw5fszffl5pkpa6s6wjnkiv6lm5k618s32sp60kvmvpy7a2v9kg";
+}
+</programlisting>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Better: This is ok, but an archive fetch will still be faster.
+<programlisting>
+src = fetchgit {
+  url = "https://github.com/NixOS/nix.git";
+  rev = "1f795f9f44607cc5bec70d1300150bfefcef2aae";
+  sha256 = "1cw5fszffl5pkpa6s6wjnkiv6lm5k618s32sp60kvmvpy7a2v9kg";
+}
+</programlisting>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Best: Fetches a snapshot archive and you get the rev you want.
+<programlisting>
+src = fetchFromGitHub {
+  owner = "NixOS";
+  repo = "nix";
+  rev = "1f795f9f44607cc5bec70d1300150bfefcef2aae";
+  sha256 = "1i2yxndxb6yc9l6c99pypbd92lfq5aac4klq7y2v93c9qvx2cgpc";
+}
+</programlisting>
+      Find the value to put as <literal>sha256</literal> by running <literal>nix run -f '&lt;nixpkgs&gt;' nix-prefetch-github -c nix-prefetch-github --rev 1f795f9f44607cc5bec70d1300150bfefcef2aae NixOS nix</literal> or <literal>nix-prefetch-url --unpack https://github.com/NixOS/nix/archive/1f795f9f44607cc5bec70d1300150bfefcef2aae.tar.gz</literal>.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+ </section>
+ <section xml:id="sec-source-hashes">
+  <title>Obtaining source hash</title>
+
+  <para>
+   Preferred source hash type is sha256. There are several ways to get it.
+  </para>
+
+  <orderedlist>
+   <listitem>
+    <para>
+     Prefetch URL (with <literal>nix-prefetch-<replaceable>XXX</replaceable> <replaceable>URL</replaceable></literal>, where <replaceable>XXX</replaceable> is one of <literal>url</literal>, <literal>git</literal>, <literal>hg</literal>, <literal>cvs</literal>, <literal>bzr</literal>, <literal>svn</literal>). Hash is printed to stdout.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Prefetch by package source (with <literal>nix-prefetch-url '&lt;nixpkgs&gt;' -A <replaceable>PACKAGE</replaceable>.src</literal>, where <replaceable>PACKAGE</replaceable> is package attribute name). Hash is printed to stdout.
+    </para>
+    <para>
+     This works well when you've upgraded existing package version and want to find out new hash, but is useless if package can't be accessed by attribute or package has multiple sources (<literal>.srcs</literal>, architecture-dependent sources, etc).
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Upstream provided hash: use it when upstream provides <literal>sha256</literal> or <literal>sha512</literal> (when upstream provides <literal>md5</literal>, don't use it, compute <literal>sha256</literal> instead).
+    </para>
+    <para>
+     A little nuance is that <literal>nix-prefetch-*</literal> tools produce hash encoded with <literal>base32</literal>, but upstream usually provides hexadecimal (<literal>base16</literal>) encoding. Fetchers understand both formats. Nixpkgs does not standardize on any one format.
+    </para>
+    <para>
+     You can convert between formats with nix-hash, for example:
+<screen>
+<prompt>$ </prompt>nix-hash --type sha256 --to-base32 <replaceable>HASH</replaceable>
+</screen>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Extracting hash from local source tarball can be done with <literal>sha256sum</literal>. Use <literal>nix-prefetch-url file:///path/to/tarball </literal> if you want base32 hash.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Fake hash: set fake hash in package expression, perform build and extract correct hash from error Nix prints.
+    </para>
+    <para>
+     For package updates it is enough to change one symbol to make hash fake. For new packages, you can use <literal>lib.fakeSha256</literal>, <literal>lib.fakeSha512</literal> or any other fake hash.
+    </para>
+    <para>
+     This is last resort method when reconstructing source URL is non-trivial and <literal>nix-prefetch-url -A</literal> isn't applicable (for example, <link xlink:href="https://github.com/NixOS/nixpkgs/blob/d2ab091dd308b99e4912b805a5eb088dd536adb9/pkgs/applications/video/kodi/default.nix#L73"> one of <literal>kodi</literal> dependencies</link>). The easiest way then would be replace hash with a fake one and rebuild. Nix build will fail and error message will contain desired hash.
+    </para>
+    <warning>
+     <para>
+      This method has security problems. Check below for details.
+     </para>
+    </warning>
+   </listitem>
+  </orderedlist>
+
+  <section xml:id="sec-source-hashes-security">
+   <title>Obtaining hashes securely</title>
+
+   <para>
+    Let's say Man-in-the-Middle (MITM) sits close to your network. Then instead of fetching source you can fetch malware, and instead of source hash you get hash of malware. Here are security considerations for this scenario:
+   </para>
+
+   <itemizedlist>
+    <listitem>
+     <para>
+      <literal>http://</literal> URLs are not secure to prefetch hash from;
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      hashes from upstream (in method 3) should be obtained via secure protocol;
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      <literal>https://</literal> URLs are secure in methods 1, 2, 3;
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      <literal>https://</literal> URLs are not secure in method 5. When obtaining hashes with fake hash method, TLS checks are disabled. So refetch source hash from several different networks to exclude MITM scenario. Alternatively, use fake hash method to make Nix error, but instead of extracting hash from error, extract <literal>https://</literal> URL and prefetch it with method 1.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </section>
+ </section>
+ <section xml:id="sec-patches">
+  <title>Patches</title>
+
+  <para>
+   Patches available online should be retrieved using <literal>fetchpatch</literal>.
+  </para>
+
+  <para>
+<programlisting>
+patches = [
+  (fetchpatch {
+    name = "fix-check-for-using-shared-freetype-lib.patch";
+    url = "http://git.ghostscript.com/?p=ghostpdl.git;a=patch;h=8f5d285";
+    sha256 = "1f0k043rng7f0rfl9hhb89qzvvksqmkrikmm38p61yfx51l325xr";
+  })
+];
+</programlisting>
+  </para>
+
+  <para>
+   Otherwise, you can add a <literal>.patch</literal> file to the <literal>nixpkgs</literal> repository. In the interest of keeping our maintenance burden to a minimum, only patches that are unique to <literal>nixpkgs</literal> should be added in this way.
+  </para>
+
+  <para>
+<programlisting>
+patches = [ ./0001-changes.patch ];
+</programlisting>
+  </para>
+
+  <para>
+   If you do need to do create this sort of patch file, one way to do so is with git:
+   <orderedlist>
+    <listitem>
+     <para>
+      Move to the root directory of the source code you're patching.
+<screen>
+<prompt>$ </prompt>cd the/program/source</screen>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      If a git repository is not already present, create one and stage all of the source files.
+<screen>
+<prompt>$ </prompt>git init
+<prompt>$ </prompt>git add .</screen>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Edit some files to make whatever changes need to be included in the patch.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Use git to create a diff, and pipe the output to a patch file:
+<screen>
+<prompt>$ </prompt>git diff > nixpkgs/pkgs/the/package/0001-changes.patch</screen>
+     </para>
+    </listitem>
+   </orderedlist>
+  </para>
+ </section>
+</chapter>

sources/nixpkgs/doc/contributing/contributing-to-documentation.xml

@@ -0,0 +1,30 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-contributing">
+ <title>Contributing to this documentation</title>
+ <para>
+  The DocBook sources of the Nixpkgs manual are in the <filename
+xlink:href="https://github.com/NixOS/nixpkgs/tree/master/doc">doc</filename> subdirectory of the Nixpkgs repository.
+ </para>
+ <para>
+  You can quickly check your edits with <command>make</command>:
+ </para>
+<screen>
+<prompt>$ </prompt>cd /path/to/nixpkgs/doc
+<prompt>$ </prompt>nix-shell
+<prompt>[nix-shell]$ </prompt>make
+</screen>
+ <para>
+  If you experience problems, run <command>make debug</command> to help understand the docbook errors.
+ </para>
+ <para>
+  After making modifications to the manual, it's important to build it before committing. You can do that as follows:
+<screen>
+<prompt>$ </prompt>cd /path/to/nixpkgs/doc
+<prompt>$ </prompt>nix-shell
+<prompt>[nix-shell]$ </prompt>make clean
+<prompt>[nix-shell]$ </prompt>nix-build .
+</screen>
+  If the build succeeds, the manual will be in <filename>./result/share/doc/nixpkgs/manual.html</filename>.
+ </para>
+</chapter>

sources/nixpkgs/doc/contributing/quick-start.xml

@@ -0,0 +1,153 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-quick-start">
+ <title>Quick Start to Adding a Package</title>
+ <para>
+  To add a package to Nixpkgs:
+  <orderedlist>
+   <listitem>
+    <para>
+     Checkout the Nixpkgs source tree:
+<screen>
+<prompt>$ </prompt>git clone https://github.com/NixOS/nixpkgs
+<prompt>$ </prompt>cd nixpkgs</screen>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Find a good place in the Nixpkgs tree to add the Nix expression for your package. For instance, a library package typically goes into <filename>pkgs/development/libraries/<replaceable>pkgname</replaceable></filename>, while a web browser goes into <filename>pkgs/applications/networking/browsers/<replaceable>pkgname</replaceable></filename>. See <xref linkend="sec-organisation" /> for some hints on the tree organisation. Create a directory for your package, e.g.
+<screen>
+<prompt>$ </prompt>mkdir pkgs/development/libraries/libfoo</screen>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     In the package directory, create a Nix expression — a piece of code that describes how to build the package. In this case, it should be a <emphasis>function</emphasis> that is called with the package dependencies as arguments, and returns a build of the package in the Nix store. The expression should usually be called <filename>default.nix</filename>.
+<screen>
+<prompt>$ </prompt>emacs pkgs/development/libraries/libfoo/default.nix
+<prompt>$ </prompt>git add pkgs/development/libraries/libfoo/default.nix</screen>
+    </para>
+    <para>
+     You can have a look at the existing Nix expressions under <filename>pkgs/</filename> to see how it’s done. Here are some good ones:
+     <itemizedlist>
+      <listitem>
+       <para>
+        GNU Hello: <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/hello/default.nix"><filename>pkgs/applications/misc/hello/default.nix</filename></link>. Trivial package, which specifies some <varname>meta</varname> attributes which is good practice.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        GNU cpio: <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/archivers/cpio/default.nix"><filename>pkgs/tools/archivers/cpio/default.nix</filename></link>. Also a simple package. The generic builder in <varname>stdenv</varname> does everything for you. It has no dependencies beyond <varname>stdenv</varname>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        GNU Multiple Precision arithmetic library (GMP): <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/libraries/gmp/5.1.x.nix"><filename>pkgs/development/libraries/gmp/5.1.x.nix</filename></link>. Also done by the generic builder, but has a dependency on <varname>m4</varname>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Pan, a GTK-based newsreader: <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/networking/newsreaders/pan/default.nix"><filename>pkgs/applications/networking/newsreaders/pan/default.nix</filename></link>. Has an optional dependency on <varname>gtkspell</varname>, which is only built if <varname>spellCheck</varname> is <literal>true</literal>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Apache HTTPD: <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/servers/http/apache-httpd/2.4.nix"><filename>pkgs/servers/http/apache-httpd/2.4.nix</filename></link>. A bunch of optional features, variable substitutions in the configure flags, a post-install hook, and miscellaneous hackery.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Thunderbird: <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/networking/mailreaders/thunderbird/default.nix"><filename>pkgs/applications/networking/mailreaders/thunderbird/default.nix</filename></link>. Lots of dependencies.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        JDiskReport, a Java utility: <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/misc/jdiskreport/default.nix"><filename>pkgs/tools/misc/jdiskreport/default.nix</filename></link> (and the <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/misc/jdiskreport/builder.sh">builder</link>). Nixpkgs doesn’t have a decent <varname>stdenv</varname> for Java yet so this is pretty ad-hoc.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        XML::Simple, a Perl module: <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/perl-packages.nix"><filename>pkgs/top-level/perl-packages.nix</filename></link> (search for the <varname>XMLSimple</varname> attribute). Most Perl modules are so simple to build that they are defined directly in <filename>perl-packages.nix</filename>; no need to make a separate file for them.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Adobe Reader: <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/adobe-reader/default.nix"><filename>pkgs/applications/misc/adobe-reader/default.nix</filename></link>. Shows how binary-only packages can be supported. In particular the <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/adobe-reader/builder.sh">builder</link> uses <command>patchelf</command> to set the RUNPATH and ELF interpreter of the executables so that the right libraries are found at runtime.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+    <para>
+     Some notes:
+     <itemizedlist>
+      <listitem>
+       <para>
+        All <varname linkend="chap-meta">meta</varname> attributes are optional, but it’s still a good idea to provide at least the <varname>description</varname>, <varname>homepage</varname> and <varname
+          linkend="sec-meta-license">license</varname>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        You can use <command>nix-prefetch-url</command> <replaceable>url</replaceable> to get the SHA-256 hash of source distributions. There are similar commands as <command>nix-prefetch-git</command> and <command>nix-prefetch-hg</command> available in <literal>nix-prefetch-scripts</literal> package.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        A list of schemes for <literal>mirror://</literal> URLs can be found in <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/fetchurl/mirrors.nix"><filename>pkgs/build-support/fetchurl/mirrors.nix</filename></link>.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+    <para>
+     The exact syntax and semantics of the Nix expression language, including the built-in function, are described in the Nix manual in the <link
+    xlink:href="http://hydra.nixos.org/job/nix/trunk/tarball/latest/download-by-type/doc/manual/#chap-writing-nix-expressions">chapter on writing Nix expressions</link>.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Add a call to the function defined in the previous step to <link
+    xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/all-packages.nix"><filename>pkgs/top-level/all-packages.nix</filename></link> with some descriptive name for the variable, e.g. <varname>libfoo</varname>.
+<screen>
+<prompt>$ </prompt>emacs pkgs/top-level/all-packages.nix</screen>
+    </para>
+    <para>
+     The attributes in that file are sorted by category (like “Development / Libraries”) that more-or-less correspond to the directory structure of Nixpkgs, and then by attribute name.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     To test whether the package builds, run the following command from the root of the nixpkgs source tree:
+<screen>
+<prompt>$ </prompt>nix-build -A libfoo</screen>
+     where <varname>libfoo</varname> should be the variable name defined in the previous step. You may want to add the flag <option>-K</option> to keep the temporary build directory in case something fails. If the build succeeds, a symlink <filename>./result</filename> to the package in the Nix store is created.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     If you want to install the package into your profile (optional), do
+<screen>
+<prompt>$ </prompt>nix-env -f . -iA libfoo</screen>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Optionally commit the new package and open a pull request <link
+     xlink:href="https://github.com/NixOS/nixpkgs/pulls">to nixpkgs</link>, or use <link
+     xlink:href="https://discourse.nixos.org/t/about-the-patches-category/477"> the Patches category</link> on Discourse for sending a patch without a GitHub account.
+    </para>
+   </listitem>
+  </orderedlist>
+ </para>
+</chapter>

sources/nixpkgs/doc/contributing/reviewing-contributions.xml

@@ -0,0 +1,536 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+        xmlns:xlink="http://www.w3.org/1999/xlink"
+        xmlns:xi="http://www.w3.org/2001/XInclude"
+        version="5.0"
+        xml:id="chap-reviewing-contributions">
+ <title>Reviewing contributions</title>
+ <warning>
+  <para>
+   The following section is a draft, and the policy for reviewing is still being discussed in issues such as <link
+	   xlink:href="https://github.com/NixOS/nixpkgs/issues/11166">#11166 </link> and <link
+	   xlink:href="https://github.com/NixOS/nixpkgs/issues/20836">#20836 </link>.
+  </para>
+ </warning>
+ <para>
+  The Nixpkgs project receives a fairly high number of contributions via GitHub pull requests. Reviewing and approving these is an important task and a way to contribute to the project.
+ </para>
+ <para>
+  The high change rate of Nixpkgs makes any pull request that remains open for too long subject to conflicts that will require extra work from the submitter or the merger. Reviewing pull requests in a timely manner and being responsive to the comments is the key to avoid this issue. GitHub provides sort filters that can be used to see the <link
+  xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+sort%3Aupdated-desc">most recently</link> and the <link
+  xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+sort%3Aupdated-asc">least recently</link> updated pull requests. We highly encourage looking at <link xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+review%3Anone+status%3Asuccess+-label%3A%222.status%3A+work-in-progress%22+no%3Aproject+no%3Aassignee+no%3Amilestone"> this list of ready to merge, unreviewed pull requests</link>.
+ </para>
+ <para>
+  When reviewing a pull request, please always be nice and polite. Controversial changes can lead to controversial opinions, but it is important to respect every community member and their work.
+ </para>
+ <para>
+  GitHub provides reactions as a simple and quick way to provide feedback to pull requests or any comments. The thumb-down reaction should be used with care and if possible accompanied with some explanation so the submitter has directions to improve their contribution.
+ </para>
+ <para>
+  pull request reviews should include a list of what has been reviewed in a comment, so other reviewers and mergers can know the state of the review.
+ </para>
+ <para>
+  All the review template samples provided in this section are generic and meant as examples. Their usage is optional and the reviewer is free to adapt them to their liking.
+ </para>
+ <section xml:id="reviewing-contributions-package-updates">
+  <title>Package updates</title>
+
+  <para>
+   A package update is the most trivial and common type of pull request. These pull requests mainly consist of updating the version part of the package name and the source hash.
+  </para>
+
+  <para>
+   It can happen that non-trivial updates include patches or more complex changes.
+  </para>
+
+  <para>
+   Reviewing process:
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Add labels to the pull request. (Requires commit rights)
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <literal>8.has: package (update)</literal> and any topic label that fit the updated package.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the package versioning fits the guidelines.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the commit text fits the guidelines.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the package maintainers are notified.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <link xlink:href="https://help.github.com/articles/about-codeowners/">CODEOWNERS</link> will make GitHub notify users based on the submitted changes, but it can happen that it misses some of the package maintainers.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the meta field information is correct.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       License can change with version updates, so it should be checked to match the upstream license.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       If the package has no maintainer, a maintainer must be set. This can be the update submitter or a community member that accepts to take maintainership of the package.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the code contains no typos.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Building the package locally.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       pull requests are often targeted to the master or staging branch, and building the pull request locally when it is submitted can trigger many source builds.
+      </para>
+      <para>
+       It is possible to rebase the changes on nixos-unstable or nixpkgs-unstable for easier review by running the following commands from a nixpkgs clone.
+<screen>
+<prompt>$ </prompt>git fetch origin nixos-unstable <co xml:id='reviewing-rebase-2' />
+<prompt>$ </prompt>git fetch origin pull/PRNUMBER/head <co xml:id='reviewing-rebase-3' />
+<prompt>$ </prompt>git rebase --onto nixos-unstable BASEBRANCH FETCH_HEAD <co
+  xml:id='reviewing-rebase-4' />
+</screen>
+       <calloutlist>
+        <callout arearefs='reviewing-rebase-2'>
+         <para>
+          Fetching the nixos-unstable branch.
+         </para>
+        </callout>
+        <callout arearefs='reviewing-rebase-3'>
+         <para>
+          Fetching the pull request changes, <varname>PRNUMBER</varname> is the number at the end of the pull request title and <varname>BASEBRANCH</varname> the base branch of the pull request.
+         </para>
+        </callout>
+        <callout arearefs='reviewing-rebase-4'>
+         <para>
+          Rebasing the pull request changes to the nixos-unstable branch.
+         </para>
+        </callout>
+       </calloutlist>
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       The <link xlink:href="https://github.com/Mic92/nixpkgs-review">nixpkgs-review</link> tool can be used to review a pull request content in a single command. <varname>PRNUMBER</varname> should be replaced by the number at the end of the pull request title. You can also provide the full github pull request url.
+      </para>
+<screen>
+<prompt>$ </prompt>nix-shell -p nixpkgs-review --run "nixpkgs-review pr PRNUMBER"
+</screen>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Running every binary.
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <example xml:id="reviewing-contributions-sample-package-update">
+   <title>Sample template for a package update review</title>
+<screen>
+##### Reviewed points
+
+- [ ] package name fits guidelines
+- [ ] package version fits guidelines
+- [ ] package build on ARCHITECTURE
+- [ ] executables tested on ARCHITECTURE
+- [ ] all depending packages build
+
+##### Possible improvements
+
+##### Comments
+
+</screen>
+  </example>
+ </section>
+ <section xml:id="reviewing-contributions-new-packages">
+  <title>New packages</title>
+
+  <para>
+   New packages are a common type of pull requests. These pull requests consists in adding a new nix-expression for a package.
+  </para>
+
+  <para>
+   Reviewing process:
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Add labels to the pull request. (Requires commit rights)
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <literal>8.has: package (new)</literal> and any topic label that fit the new package.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the package versioning is fitting the guidelines.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the commit name is fitting the guidelines.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the meta field contains correct information.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       License must be checked to be fitting upstream license.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       Platforms should be set or the package will not get binary substitutes.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       A maintainer must be set. This can be the package submitter or a community member that accepts to take maintainership of the package.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the code contains no typos.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure the package source.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       Mirrors urls should be used when available.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       The most appropriate function should be used (e.g. packages from GitHub should use <literal>fetchFromGitHub</literal>).
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Building the package locally.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Running every binary.
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <example xml:id="reviewing-contributions-sample-new-package">
+   <title>Sample template for a new package review</title>
+<screen>
+##### Reviewed points
+
+- [ ] package path fits guidelines
+- [ ] package name fits guidelines
+- [ ] package version fits guidelines
+- [ ] package build on ARCHITECTURE
+- [ ] executables tested on ARCHITECTURE
+- [ ] `meta.description` is set and fits guidelines
+- [ ] `meta.license` fits upstream license
+- [ ] `meta.platforms` is set
+- [ ] `meta.maintainers` is set
+- [ ] build time only dependencies are declared in `nativeBuildInputs`
+- [ ] source is fetched using the appropriate function
+- [ ] phases are respected
+- [ ] patches that are remotely available are fetched with `fetchpatch`
+
+##### Possible improvements
+
+##### Comments
+
+</screen>
+  </example>
+ </section>
+ <section xml:id="reviewing-contributions-module-updates">
+  <title>Module updates</title>
+
+  <para>
+   Module updates are submissions changing modules in some ways. These often contains changes to the options or introduce new options.
+  </para>
+
+  <para>
+   Reviewing process
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Add labels to the pull request. (Requires commit rights)
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <literal>8.has: module (update)</literal> and any topic label that fit the module.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the module maintainers are notified.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <link xlink:href="https://help.github.com/articles/about-codeowners/">CODEOWNERS</link> will make GitHub notify users based on the submitted changes, but it can happen that it misses some of the package maintainers.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the module tests, if any, are succeeding.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the introduced options are correct.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       Type should be appropriate (string related types differs in their merging capabilities, <literal>optionSet</literal> and <literal>string</literal> types are deprecated).
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       Description, default and example should be provided.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that option changes are backward compatible.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <literal>mkRenamedOptionModule</literal> and <literal>mkAliasOptionModule</literal> functions provide way to make option changes backward compatible.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that removed options are declared with <literal>mkRemovedOptionModule</literal>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that changes that are not backward compatible are mentioned in release notes.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that documentations affected by the change is updated.
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <example xml:id="reviewing-contributions-sample-module-update">
+   <title>Sample template for a module update review</title>
+<screen>
+##### Reviewed points
+
+- [ ] changes are backward compatible
+- [ ] removed options are declared with `mkRemovedOptionModule`
+- [ ] changes that are not backward compatible are documented in release notes
+- [ ] module tests succeed on ARCHITECTURE
+- [ ] options types are appropriate
+- [ ] options description is set
+- [ ] options example is provided
+- [ ] documentation affected by the changes is updated
+
+##### Possible improvements
+
+##### Comments
+
+</screen>
+  </example>
+ </section>
+ <section xml:id="reviewing-contributions-new-modules">
+  <title>New modules</title>
+
+  <para>
+   New modules submissions introduce a new module to NixOS.
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Add labels to the pull request. (Requires commit rights)
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <literal>8.has: module (new)</literal> and any topic label that fit the module.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the module tests, if any, are succeeding.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the introduced options are correct.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       Type should be appropriate (string related types differs in their merging capabilities, <literal>optionSet</literal> and <literal>string</literal> types are deprecated).
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       Description, default and example should be provided.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that module <literal>meta</literal> field is present
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       Maintainers should be declared in <literal>meta.maintainers</literal>.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       Module documentation should be declared with <literal>meta.doc</literal>.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the module respect other modules functionality.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       For example, enabling a module should not open firewall ports by default.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+  </itemizedlist>
+
+  <example xml:id="reviewing-contributions-sample-new-module">
+   <title>Sample template for a new module review</title>
+<screen>
+##### Reviewed points
+
+- [ ] module path fits the guidelines
+- [ ] module tests succeed on ARCHITECTURE
+- [ ] options have appropriate types
+- [ ] options have default
+- [ ] options have example
+- [ ] options have descriptions
+- [ ] No unneeded package is added to environment.systemPackages
+- [ ] meta.maintainers is set
+- [ ] module documentation is declared in meta.doc
+
+##### Possible improvements
+
+##### Comments
+
+</screen>
+  </example>
+ </section>
+ <section xml:id="reviewing-contributions-other-submissions">
+  <title>Other submissions</title>
+
+  <para>
+   Other type of submissions requires different reviewing steps.
+  </para>
+
+  <para>
+   If you consider having enough knowledge and experience in a topic and would like to be a long-term reviewer for related submissions, please contact the current reviewers for that topic. They will give you information about the reviewing process. The main reviewers for a topic can be hard to find as there is no list, but checking past pull requests to see who reviewed or git-blaming the code to see who committed to that topic can give some hints.
+  </para>
+
+  <para>
+   Container system, boot system and library changes are some examples of the pull requests fitting this category.
+  </para>
+ </section>
+ <section xml:id="reviewing-contributions--merging-pull-requests">
+  <title>Merging pull requests</title>
+
+  <para>
+   It is possible for community members that have enough knowledge and experience on a special topic to contribute by merging pull requests.
+  </para>
+
+  <para>
+   TODO: add the procedure to request merging rights.
+  </para>
+
+<!--
+The following paragraph about how to deal with unactive contributors is just a
+proposition and should be modified to what the community agrees to be the right
+policy.
+
+<para>Please note that contributors with commit rights unactive for more than
+  three months will have their commit rights revoked.</para>
+-->
+
+  <para>
+   In a case a contributor definitively leaves the Nix community, they should create an issue or post on <link
+   xlink:href="https://discourse.nixos.org">Discourse</link> with references of packages and modules they maintain so the maintainership can be taken over by other contributors.
+  </para>
+ </section>
+</chapter>

sources/nixpkgs/doc/contributing/submitting-changes.xml

@@ -0,0 +1,462 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-submitting-changes">
+ <title>Submitting changes</title>
+ <section xml:id="submitting-changes-making-patches">
+  <title>Making patches</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Read <link xlink:href="https://nixos.org/nixpkgs/manual/">Manual (How to write packages for Nix)</link>.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Fork the repository on GitHub.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Create a branch for your future fix.
+     <itemizedlist>
+      <listitem>
+       <para>
+        You can make branch from a commit of your local <command>nixos-version</command>. That will help you to avoid additional local compilations. Because you will receive packages from binary cache.
+        <itemizedlist>
+         <listitem>
+          <para>
+           For example: <command>nixos-version</command> returns <command>15.05.git.0998212 (Dingo)</command>. So you can do:
+          </para>
+         </listitem>
+        </itemizedlist>
+<screen>
+<prompt>$ </prompt>git checkout 0998212
+<prompt>$ </prompt>git checkout -b 'fix/pkg-name-update'
+</screen>
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Please avoid working directly on the <command>master</command> branch.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Make commits of logical units.
+     <itemizedlist>
+      <listitem>
+       <para>
+        If you removed pkgs, made some major NixOS changes etc., write about them in <command>nixos/doc/manual/release-notes/rl-unstable.xml</command>.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Check for unnecessary whitespace with <command>git diff --check</command> before committing.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Format the commit in a following way:
+    </para>
+<programlisting>
+(pkg-name | nixos/&lt;module>): (from -> to | init at version | refactor | etc)
+Additional information.
+</programlisting>
+    <itemizedlist>
+     <listitem>
+      <para>
+       Examples:
+       <itemizedlist>
+        <listitem>
+         <para>
+          <command>nginx: init at 2.0.1</command>
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          <command>firefox: 54.0.1 -> 55.0</command>
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          <command>nixos/hydra: add bazBaz option</command>
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          <command>nixos/nginx: refactor config generation</command>
+         </para>
+        </listitem>
+       </itemizedlist>
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Test your changes. If you work with
+     <itemizedlist>
+      <listitem>
+       <para>
+        nixpkgs:
+        <itemizedlist>
+         <listitem>
+          <para>
+           update pkg ->
+           <itemizedlist>
+            <listitem>
+             <para>
+              <command>nix-env -i pkg-name -f &lt;path to your local nixpkgs folder&gt;</command>
+             </para>
+            </listitem>
+           </itemizedlist>
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           add pkg ->
+           <itemizedlist>
+            <listitem>
+             <para>
+              Make sure it's in <command>pkgs/top-level/all-packages.nix</command>
+             </para>
+            </listitem>
+            <listitem>
+             <para>
+              <command>nix-env -i pkg-name -f &lt;path to your local nixpkgs folder&gt;</command>
+             </para>
+            </listitem>
+           </itemizedlist>
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           <emphasis>If you don't want to install pkg in you profile</emphasis>.
+           <itemizedlist>
+            <listitem>
+             <para>
+              <command>nix-build -A pkg-attribute-name &lt;path to your local nixpkgs folder&gt;/default.nix</command> and check results in the folder <command>result</command>. It will appear in the same directory where you did <command>nix-build</command>.
+             </para>
+            </listitem>
+           </itemizedlist>
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If you did <command>nix-env -i pkg-name</command> you can do <command>nix-env -e pkg-name</command> to uninstall it from your system.
+          </para>
+         </listitem>
+        </itemizedlist>
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        NixOS and its modules:
+        <itemizedlist>
+         <listitem>
+          <para>
+           You can add new module to your NixOS configuration file (usually it's <command>/etc/nixos/configuration.nix</command>). And do <command>sudo nixos-rebuild test -I nixpkgs=&lt;path to your local nixpkgs folder&gt; --fast</command>.
+          </para>
+         </listitem>
+        </itemizedlist>
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     If you have commits <command>pkg-name: oh, forgot to insert whitespace</command>: squash commits in this case. Use <command>git rebase -i</command>.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Rebase you branch against current <command>master</command>.
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+ <section xml:id="submitting-changes-submitting-changes">
+  <title>Submitting changes</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Push your changes to your fork of nixpkgs.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Create pull request:
+     <itemizedlist>
+      <listitem>
+       <para>
+        Write the title in format <command>(pkg-name | nixos/&lt;module>): improvement</command>.
+        <itemizedlist>
+         <listitem>
+          <para>
+           If you update the pkg, write versions <command>from -> to</command>.
+          </para>
+         </listitem>
+        </itemizedlist>
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Write in comment if you have tested your patch. Do not rely much on <command>TravisCI</command>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        If you make an improvement, write about your motivation.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Notify maintainers of the package. For example add to the message: <command>cc @jagajaga @domenkozar</command>.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+ <section xml:id="submitting-changes-submitting-security-fixes">
+  <title>Submitting security fixes</title>
+
+  <para>
+   Security fixes are submitted in the same way as other changes and thus the same guidelines apply.
+  </para>
+
+  <para>
+   If the security fix comes in the form of a patch and a CVE is available, then the name of the patch should be the CVE identifier, so e.g. <literal>CVE-2019-13636.patch</literal> in the case of a patch that is included in the Nixpkgs tree. If a patch is fetched the name needs to be set as well, e.g.:
+  </para>
+
+<programlisting>
+   (fetchpatch {
+     name = "CVE-2019-11068.patch";
+     url = "https://gitlab.gnome.org/GNOME/libxslt/commit/e03553605b45c88f0b4b2980adfbbb8f6fca2fd6.patch";
+     sha256 = "0pkpb4837km15zgg6h57bncp66d5lwrlvkr73h0lanywq7zrwhj8";
+   })
+  </programlisting>
+
+  <para>
+   If a security fix applies to both master and a stable release then, similar to regular changes, they are preferably delivered via master first and cherry-picked to the release branch.
+  </para>
+
+  <para>
+   Critical security fixes may by-pass the staging branches and be delivered directly to release branches such as <literal>master</literal> and <literal>release-*</literal>.
+  </para>
+ </section>
+ <section xml:id="submitting-changes-pull-request-template">
+  <title>Pull Request Template</title>
+
+  <para>
+   The pull request template helps determine what steps have been made for a contribution so far, and will help guide maintainers on the status of a change. The motivation section of the PR should include any extra details the title does not address and link any existing issues related to the pull request.
+  </para>
+
+  <para>
+   When a PR is created, it will be pre-populated with some checkboxes detailed below:
+  </para>
+
+  <section xml:id="submitting-changes-tested-with-sandbox">
+   <title>Tested using sandboxing</title>
+
+   <para>
+    When sandbox builds are enabled, Nix will setup an isolated environment for each build process. It is used to remove further hidden dependencies set by the build environment to improve reproducibility. This includes access to the network during the build outside of <function>fetch*</function> functions and files outside the Nix store. Depending on the operating system access to other resources are blocked as well (ex. inter process communication is isolated on Linux); see <link
+      xlink:href="https://nixos.org/nix/manual/#conf-sandbox">sandbox</link> in Nix manual for details.
+   </para>
+
+   <para>
+    Sandboxing is not enabled by default in Nix due to a small performance hit on each build. In pull requests for <link
+        xlink:href="https://github.com/NixOS/nixpkgs/">nixpkgs</link> people are asked to test builds with sandboxing enabled (see <literal>Tested using sandboxing</literal> in the pull request template) because in<link
+        xlink:href="https://nixos.org/hydra/">https://nixos.org/hydra/</link> sandboxing is also used.
+   </para>
+
+   <para>
+    Depending if you use NixOS or other platforms you can use one of the following methods to enable sandboxing <emphasis role="bold">before</emphasis> building the package:
+    <itemizedlist>
+     <listitem>
+      <para>
+       <emphasis role="bold">Globally enable sandboxing on NixOS</emphasis>: add the following to <filename>configuration.nix</filename>
+<screen>nix.useSandbox = true;</screen>
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       <emphasis role="bold">Globally enable sandboxing on non-NixOS platforms</emphasis>: add the following to: <filename>/etc/nix/nix.conf</filename>
+<screen>sandbox = true</screen>
+      </para>
+     </listitem>
+    </itemizedlist>
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-platform-diversity">
+   <title>Built on platform(s)</title>
+
+   <para>
+    Many Nix packages are designed to run on multiple platforms. As such, it's important to let the maintainer know which platforms your changes have been tested on. It's not always practical to test a change on all platforms, and is not required for a pull request to be merged. Only check the systems you tested the build on in this section.
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-nixos-tests">
+   <title>Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)</title>
+
+   <para>
+    Packages with automated tests are much more likely to be merged in a timely fashion because it doesn't require as much manual testing by the maintainer to verify the functionality of the package. If there are existing tests for the package, they should be run to verify your changes do not break the tests. Tests only apply to packages with NixOS modules defined and can only be run on Linux. For more details on writing and running tests, see the <link
+        xlink:href="https://nixos.org/nixos/manual/index.html#sec-nixos-tests">section in the NixOS manual</link>.
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-tested-compilation">
+   <title>Tested compilation of all pkgs that depend on this change using <command>nixpkgs-review</command></title>
+
+   <para>
+    If you are updating a package's version, you can use nixpkgs-review to make sure all packages that depend on the updated package still compile correctly. The <command>nixpkgs-review</command> utility can look for and build all dependencies either based on uncommited changes with the <literal>wip</literal> option or specifying a github pull request number.
+   </para>
+
+   <para>
+    review changes from pull request number 12345:
+    <screen>nix run nixpkgs.nixpkgs-review -c nixpkgs-review pr 12345</screen>
+   </para>
+
+   <para>
+    review uncommitted changes:
+    <screen>nix run nixpkgs.nixpkgs-review -c nixpkgs-review wip</screen>
+   </para>
+
+   <para>
+    review changes from last commit:
+    <screen>nix run nixpkgs.nixpkgs-review -c nixpkgs-review rev HEAD</screen>
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-tested-execution">
+   <title>Tested execution of all binary files (usually in <filename>./result/bin/</filename>)</title>
+
+   <para>
+    It's important to test any executables generated by a build when you change or create a package in nixpkgs. This can be done by looking in <filename>./result/bin</filename> and running any files in there, or at a minimum, the main executable for the package. For example, if you make a change to <package>texlive</package>, you probably would only check the binaries associated with the change you made rather than testing all of them.
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-contribution-standards">
+   <title>Meets Nixpkgs contribution standards</title>
+
+   <para>
+    The last checkbox is fits <link
+        xlink:href="https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md">CONTRIBUTING.md</link>. The contributing document has detailed information on standards the Nix community has for commit messages, reviews, licensing of contributions you make to the project, etc... Everyone should read and understand the standards the community has for contributing before submitting a pull request.
+   </para>
+  </section>
+ </section>
+ <section xml:id="submitting-changes-hotfixing-pull-requests">
+  <title>Hotfixing pull requests</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Make the appropriate changes in you branch.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Don't create additional commits, do
+     <itemizedlist>
+      <listitem>
+       <para>
+        <command>git rebase -i</command>
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        <command>git push --force</command> to your branch.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+ <section xml:id="submitting-changes-commit-policy">
+  <title>Commit policy</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Commits must be sufficiently tested before being merged, both for the master and staging branches.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Hydra builds for master and staging should not be used as testing platform, it's a build farm for changes that have been already tested.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     When changing the bootloader installation process, extra care must be taken. Grub installations cannot be rolled back, hence changes may break people's installations forever. For any non-trivial change to the bootloader please file a PR asking for review, especially from @edolstra.
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <section xml:id="submitting-changes-master-branch">
+   <title>Master branch</title>
+   <para>
+    The <literal>master</literal> branch is the main development branch.
+    It should only see non-breaking commits that do not cause mass rebuilds.
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-staging-branch">
+   <title>Staging branch</title>
+   <para>
+    The <literal>staging</literal> branch is a development branch where mass-rebuilds go.
+    It should only see non-breaking mass-rebuild commits.
+    That means it is not to be used for testing, and changes must have been well tested already.
+    If the branch is already in a broken state, please refrain from adding extra new breakages.
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-staging-next-branch">
+   <title>Staging-next branch</title>
+   <para>
+    The <literal>staging-next</literal> branch is for stabilizing mass-rebuilds submitted to the <literal>staging</literal> branch prior to merging them into <literal>master</literal>.
+    Mass-rebuilds should go via the <literal>staging</literal> branch.
+    It should only see non-breaking commits that are fixing issues blocking it from being merged into the <literal>master </literal> branch.
+   </para>
+   <para>
+    If the branch is already in a broken state, please refrain from adding extra new breakages. Stabilize it for a few days and then merge into master.
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-stable-release-branches">
+   <title>Stable release branches</title>
+
+   <itemizedlist>
+    <listitem>
+     <para>
+      If you're cherry-picking a commit to a stable release branch (“backporting”), always use <command>git cherry-pick -xe</command> and ensure the message contains a clear description about why this needs to be included in the stable branch.
+     </para>
+     <para>
+      An example of a cherry-picked commit would look like this:
+     </para>
+<screen>
+nixos: Refactor the world.
+
+The original commit message describing the reason why the world was torn apart.
+
+(cherry picked from commit abcdef)
+Reason: I just had a gut feeling that this would also be wanted by people from
+the stone age.
+</screen>
+    </listitem>
+   </itemizedlist>
+  </section>
+ </section>
+</chapter>

sources/nixpkgs/doc/default.nix

@@ -0,0 +1,28 @@
+{ pkgs ? (import ./.. { }), nixpkgs ? { }}:
+let
+  lib = pkgs.lib;
+  doc-support = import ./doc-support { inherit pkgs nixpkgs; };
+in pkgs.stdenv.mkDerivation {
+  name = "nixpkgs-manual";
+
+  buildInputs = with pkgs; [ pandoc libxml2 libxslt zip jing  xmlformat ];
+
+  src = ./.;
+
+  postPatch = ''
+    ln -s ${doc-support} ./doc-support/result
+  '';
+
+  installPhase = ''
+    dest="$out/share/doc/nixpkgs"
+    mkdir -p "$(dirname "$dest")"
+    mv out/html "$dest"
+    mv "$dest/index.html" "$dest/manual.html"
+
+    mv out/epub/manual.epub "$dest/nixpkgs-manual.epub"
+
+    mkdir -p $out/nix-support/
+    echo "doc manual $dest manual.html" >> $out/nix-support/hydra-build-products
+    echo "doc manual $dest nixpkgs-manual.epub" >> $out/nix-support/hydra-build-products
+  '';
+}

sources/nixpkgs/doc/doc-support/default.nix

@@ -0,0 +1,45 @@
+{ pkgs ? (import ../.. {}), nixpkgs ? { }}:
+let
+  locationsXml = import ./lib-function-locations.nix { inherit pkgs nixpkgs; };
+  functionDocs = import ./lib-function-docs.nix { inherit locationsXml pkgs; };
+  version = pkgs.lib.version;
+
+  epub-xsl = pkgs.writeText "epub.xsl" ''
+    <?xml version='1.0'?>
+    <xsl:stylesheet
+      xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+      version="1.0">
+      <xsl:import href="${pkgs.docbook_xsl_ns}/xml/xsl/docbook/epub/docbook.xsl" />
+      <xsl:import href="${./parameters.xml}"/>
+    </xsl:stylesheet>
+  '';
+
+  xhtml-xsl = pkgs.writeText "xhtml.xsl" ''
+    <?xml version='1.0'?>
+    <xsl:stylesheet
+      xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+      version="1.0">
+      <xsl:import href="${pkgs.docbook_xsl_ns}/xml/xsl/docbook/xhtml/docbook.xsl" />
+      <xsl:import href="${./parameters.xml}"/>
+    </xsl:stylesheet>
+  '';
+in pkgs.runCommand "doc-support" {}
+''
+  mkdir result
+  (
+    cd result
+    ln -s ${locationsXml} ./function-locations.xml
+    ln -s ${functionDocs} ./function-docs
+
+    ln -s ${pkgs.docbook5}/xml/rng/docbook/docbook.rng ./docbook.rng
+    ln -s ${pkgs.docbook_xsl_ns}/xml/xsl ./xsl
+    ln -s ${epub-xsl} ./epub.xsl
+    ln -s ${xhtml-xsl} ./xhtml.xsl
+
+    ln -s ${../../nixos/doc/xmlformat.conf} ./xmlformat.conf
+    ln -s ${pkgs.documentation-highlighter} ./highlightjs
+
+    echo -n "${version}" > ./version
+  )
+  mv result $out
+''

sources/nixpkgs/doc/doc-support/lib-function-docs.nix

@@ -0,0 +1,26 @@
+# Generates the documentation for library functons via nixdoc. To add
+# another library function file to this list, the include list in the
+# file `doc/functions/library.xml` must also be updated.
+
+{ pkgs ? import ./.. {}, locationsXml }:
+
+with pkgs; stdenv.mkDerivation {
+  name = "nixpkgs-lib-docs";
+  src = ./../../lib;
+
+  buildInputs = [ nixdoc ];
+  installPhase = ''
+    function docgen {
+      nixdoc -c "$1" -d "$2" -f "../lib/$1.nix"  > "$out/$1.xml"
+    }
+
+    mkdir -p $out
+    ln -s ${locationsXml} $out/locations.xml
+
+    docgen strings 'String manipulation functions'
+    docgen trivial 'Miscellaneous functions'
+    docgen lists 'List manipulation functions'
+    docgen debug 'Debugging functions'
+    docgen options 'NixOS / nixpkgs option handling'
+  '';
+}

sources/nixpkgs/doc/doc-support/lib-function-locations.nix

@@ -0,0 +1,85 @@
+{ pkgs ? (import ./.. { }), nixpkgs ? { }}:
+let
+  revision = pkgs.lib.trivial.revisionWithDefault (nixpkgs.revision or "master");
+
+  libDefPos = set:
+    builtins.map
+      (name: {
+        name = name;
+        location = builtins.unsafeGetAttrPos name set;
+      })
+      (builtins.attrNames set);
+
+  libset = toplib:
+    builtins.map
+      (subsetname: {
+        subsetname = subsetname;
+        functions = libDefPos toplib.${subsetname};
+      })
+      (builtins.filter
+        (name: builtins.isAttrs toplib.${name})
+        (builtins.attrNames toplib));
+
+  nixpkgsLib = pkgs.lib;
+
+  flattenedLibSubset = { subsetname, functions }:
+  builtins.map
+    (fn: {
+      name = "lib.${subsetname}.${fn.name}";
+      value = fn.location;
+    })
+    functions;
+
+  locatedlibsets = libs: builtins.map flattenedLibSubset (libset libs);
+  removeFilenamePrefix = prefix: filename:
+    let
+    prefixLen = (builtins.stringLength prefix) + 1; # +1 to remove the leading /
+      filenameLen = builtins.stringLength filename;
+      substr = builtins.substring prefixLen filenameLen filename;
+      in substr;
+
+  removeNixpkgs = removeFilenamePrefix (builtins.toString pkgs.path);
+
+  liblocations =
+    builtins.filter
+      (elem: elem.value != null)
+      (nixpkgsLib.lists.flatten
+        (locatedlibsets nixpkgsLib));
+
+  fnLocationRelative = { name, value }:
+    {
+      inherit name;
+      value = value // { file = removeNixpkgs value.file; };
+    };
+
+  relativeLocs = (builtins.map fnLocationRelative liblocations);
+  sanitizeId = builtins.replaceStrings
+    [ "'"      ]
+    [ "-prime" ];
+
+  urlPrefix = "https://github.com/NixOS/nixpkgs/blob/${revision}";
+  xmlstrings = (nixpkgsLib.strings.concatMapStrings
+      ({ name, value }:
+      ''
+      <section><title>${name}</title>
+        <para xml:id="${sanitizeId name}">
+        Located at
+        <link
+          xlink:href="${urlPrefix}/${value.file}#L${builtins.toString value.line}">${value.file}:${builtins.toString value.line}</link>
+        in  <literal>&lt;nixpkgs&gt;</literal>.
+        </para>
+        </section>
+      '')
+      relativeLocs);
+
+in pkgs.writeText
+    "locations.xml"
+    ''
+    <section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         version="5">
+         <title>All the locations for every lib function</title>
+         <para>This file is only for inclusion by other files.</para>
+         ${xmlstrings}
+    </section>
+    ''

sources/nixpkgs/doc/doc-support/parameters.xml

@@ -0,0 +1,14 @@
+<?xml version='1.0'?>
+<xsl:stylesheet
+    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+    version="1.0">
+ <xsl:param name="section.autolabel" select="1" />
+ <xsl:param name="section.label.includes.component.label" select="1" />
+ <xsl:param name="html.stylesheet" select="'style.css overrides.css highlightjs/mono-blue.css'" />
+ <xsl:param name="html.script" select="'./highlightjs/highlight.pack.js ./highlightjs/loader.js'" />
+ <xsl:param name="xref.with.number.and.title" select="1" />
+ <xsl:param name="use.id.as.filename" select="1" />
+ <xsl:param name="toc.section.depth" select="0" />
+ <xsl:param name="admon.style" select="''" />
+ <xsl:param name="callout.graphics.extension" select="'.svg'" />
+</xsl:stylesheet>

sources/nixpkgs/doc/functions.xml

@@ -0,0 +1,14 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="chap-functions">
+ <title>Functions reference</title>
+ <para>
+  The nixpkgs repository has several utility functions to manipulate Nix expressions.
+ </para>
+ <xi:include href="functions/library.xml" />
+ <xi:include href="functions/generators.xml" />
+ <xi:include href="functions/debug.xml" />
+ <xi:include href="functions/prefer-remote-fetch.xml" />
+ <xi:include href="functions/nix-gitignore.xml" />
+</chapter>

sources/nixpkgs/doc/functions/debug.xml

@@ -0,0 +1,14 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-debug">
+ <title>Debugging Nix Expressions</title>
+
+ <para>
+  Nix is a unityped, dynamic language, this means every value can potentially appear anywhere. Since it is also non-strict, evaluation order and what ultimately is evaluated might surprise you. Therefore it is important to be able to debug nix expressions.
+ </para>
+
+ <para>
+  In the <literal>lib/debug.nix</literal> file you will find a number of functions that help (pretty-)printing values while evaluation is runnnig. You can even specify how deep these values should be printed recursively, and transform them on the fly. Please consult the docstrings in <literal>lib/debug.nix</literal> for usage information.
+ </para>
+</section>

sources/nixpkgs/doc/functions/generators.xml

@@ -0,0 +1,74 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-generators">
+ <title>Generators</title>
+
+ <para>
+  Generators are functions that create file formats from nix data structures, e. g. for configuration files. There are generators available for: <literal>INI</literal>, <literal>JSON</literal> and <literal>YAML</literal>
+ </para>
+
+ <para>
+  All generators follow a similar call interface: <code>generatorName configFunctions data</code>, where <literal>configFunctions</literal> is an attrset of user-defined functions that format nested parts of the content. They each have common defaults, so often they do not need to be set manually. An example is <code>mkSectionName ? (name: libStr.escape [ "[" "]" ] name)</code> from the <literal>INI</literal> generator. It receives the name of a section and sanitizes it. The default <literal>mkSectionName</literal> escapes <literal>[</literal> and <literal>]</literal> with a backslash.
+ </para>
+
+ <para>
+  Generators can be fine-tuned to produce exactly the file format required by your application/service. One example is an INI-file format which uses <literal>: </literal> as separator, the strings <literal>"yes"</literal>/<literal>"no"</literal> as boolean values and requires all string values to be quoted:
+ </para>
+
+<programlisting>
+with lib;
+let
+  customToINI = generators.toINI {
+    # specifies how to format a key/value pair
+    mkKeyValue = generators.mkKeyValueDefault {
+      # specifies the generated string for a subset of nix values
+      mkValueString = v:
+             if v == true then ''"yes"''
+        else if v == false then ''"no"''
+        else if isString v then ''"${v}"''
+        # and delegats all other values to the default generator
+        else generators.mkValueStringDefault {} v;
+    } ":";
+  };
+
+# the INI file can now be given as plain old nix values
+in customToINI {
+  main = {
+    pushinfo = true;
+    autopush = false;
+    host = "localhost";
+    port = 42;
+  };
+  mergetool = {
+    merge = "diff3";
+  };
+}
+</programlisting>
+
+ <para>
+  This will produce the following INI file as nix string:
+ </para>
+
+<programlisting>
+[main]
+autopush:"no"
+host:"localhost"
+port:42
+pushinfo:"yes"
+str\:ange:"very::strange"
+
+[mergetool]
+merge:"diff3"
+</programlisting>
+
+ <note>
+  <para>
+   Nix store paths can be converted to strings by enclosing a derivation attribute like so: <code>"${drv}"</code>.
+  </para>
+ </note>
+
+ <para>
+  Detailed documentation for each generator can be found in <literal>lib/generators.nix</literal>.
+ </para>
+</section>

sources/nixpkgs/doc/functions/library.xml

@@ -0,0 +1,28 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-functions-library">
+ <title>Nixpkgs Library Functions</title>
+
+ <para>
+  Nixpkgs provides a standard library at <varname>pkgs.lib</varname>, or through <code>import &lt;nixpkgs/lib&gt;</code>.
+ </para>
+
+ <xi:include href="./library/asserts.xml" />
+
+ <xi:include href="./library/attrsets.xml" />
+
+<!-- These docs are generated via nixdoc. To add another generated
+      library function file to this list, the file
+      `lib-function-docs.nix` must also be updated. -->
+
+ <xi:include href="./library/generated/strings.xml" />
+
+ <xi:include href="./library/generated/trivial.xml" />
+
+ <xi:include href="./library/generated/lists.xml" />
+
+ <xi:include href="./library/generated/debug.xml" />
+
+ <xi:include href="./library/generated/options.xml" />
+</section>

sources/nixpkgs/doc/functions/library/asserts.xml

@@ -0,0 +1,112 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-functions-library-asserts">
+ <title>Assert functions</title>
+
+ <section xml:id="function-library-lib.asserts.assertMsg">
+  <title><function>lib.asserts.assertMsg</function></title>
+
+  <subtitle><literal>assertMsg :: Bool -> String -> Bool</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.asserts.assertMsg" />
+
+  <para>
+   Print a trace message if <literal>pred</literal> is false.
+  </para>
+
+  <para>
+   Intended to be used to augment asserts with helpful error messages.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>pred</varname>
+    </term>
+    <listitem>
+     <para>
+      Condition under which the <varname>msg</varname> should <emphasis>not</emphasis> be printed.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>msg</varname>
+    </term>
+    <listitem>
+     <para>
+      Message to print.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.asserts.assertMsg-example-false">
+   <title>Printing when the predicate is false</title>
+<programlisting><![CDATA[
+assert lib.asserts.assertMsg ("foo" == "bar") "foo is not bar, silly"
+stderr> trace: foo is not bar, silly
+stderr> assert failed
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.asserts.assertOneOf">
+  <title><function>lib.asserts.assertOneOf</function></title>
+
+  <subtitle><literal>assertOneOf :: String -> String ->
+      StringList -> Bool</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.asserts.assertOneOf" />
+
+  <para>
+   Specialized <function>asserts.assertMsg</function> for checking if <varname>val</varname> is one of the elements of <varname>xs</varname>. Useful for checking enums.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>name</varname>
+    </term>
+    <listitem>
+     <para>
+      The name of the variable the user entered <varname>val</varname> into, for inclusion in the error message.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>val</varname>
+    </term>
+    <listitem>
+     <para>
+      The value of what the user provided, to be compared against the values in <varname>xs</varname>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>xs</varname>
+    </term>
+    <listitem>
+     <para>
+      The list of valid values.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.asserts.assertOneOf-example">
+   <title>Ensuring a user provided a possible value</title>
+<programlisting><![CDATA[
+let sslLibrary = "bearssl";
+in lib.asserts.assertOneOf "sslLibrary" sslLibrary [ "openssl" "bearssl" ];
+=> false
+stderr> trace: sslLibrary must be one of "openssl", "libressl", but is: "bearssl"
+        ]]></programlisting>
+  </example>
+ </section>
+</section>

sources/nixpkgs/doc/functions/nix-gitignore.xml

@@ -0,0 +1,70 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-pkgs-nix-gitignore">
+ <title>pkgs.nix-gitignore</title>
+
+ <para>
+  <function>pkgs.nix-gitignore</function> is a function that acts similarly to <literal>builtins.filterSource</literal> but also allows filtering with the help of the gitignore format.
+ </para>
+
+ <section xml:id="sec-pkgs-nix-gitignore-usage">
+  <title>Usage</title>
+
+  <para>
+   <literal>pkgs.nix-gitignore</literal> exports a number of functions, but you'll most likely need either <literal>gitignoreSource</literal> or <literal>gitignoreSourcePure</literal>. As their first argument, they both accept either 1. a file with gitignore lines or 2. a string with gitignore lines, or 3. a list of either of the two. They will be concatenated into a single big string.
+  </para>
+
+<programlisting><![CDATA[
+{ pkgs ? import <nixpkgs> {} }:
+
+ nix-gitignore.gitignoreSource [] ./source
+     # Simplest version
+
+ nix-gitignore.gitignoreSource "supplemental-ignores\n" ./source
+     # This one reads the ./source/.gitignore and concats the auxiliary ignores
+
+ nix-gitignore.gitignoreSourcePure "ignore-this\nignore-that\n" ./source
+     # Use this string as gitignore, don't read ./source/.gitignore.
+
+ nix-gitignore.gitignoreSourcePure ["ignore-this\nignore-that\n", ~/.gitignore] ./source
+     # It also accepts a list (of strings and paths) that will be concatenated
+     # once the paths are turned to strings via readFile.
+  ]]></programlisting>
+
+  <para>
+   These functions are derived from the <literal>Filter</literal> functions by setting the first filter argument to <literal>(_: _: true)</literal>:
+  </para>
+
+<programlisting><![CDATA[
+gitignoreSourcePure = gitignoreFilterSourcePure (_: _: true);
+gitignoreSource = gitignoreFilterSource (_: _: true);
+  ]]></programlisting>
+
+  <para>
+   Those filter functions accept the same arguments the <literal>builtins.filterSource</literal> function would pass to its filters, thus <literal>fn: gitignoreFilterSourcePure fn ""</literal> should be extensionally equivalent to <literal>filterSource</literal>. The file is blacklisted iff it's blacklisted by either your filter or the gitignoreFilter.
+  </para>
+
+  <para>
+   If you want to make your own filter from scratch, you may use
+  </para>
+
+<programlisting><![CDATA[
+gitignoreFilter = ign: root: filterPattern (gitignoreToPatterns ign) root;
+  ]]></programlisting>
+ </section>
+
+ <section xml:id="sec-pkgs-nix-gitignore-usage-recursive">
+  <title>gitignore files in subdirectories</title>
+
+  <para>
+   If you wish to use a filter that would search for .gitignore files in subdirectories, just like git does by default, use this function:
+  </para>
+
+<programlisting><![CDATA[
+gitignoreFilterRecursiveSource = filter: patterns: root:
+# OR
+gitignoreRecursiveSource = gitignoreFilterSourcePure (_: _: true);
+  ]]></programlisting>
+ </section>
+</section>

sources/nixpkgs/doc/functions/prefer-remote-fetch.xml

@@ -0,0 +1,21 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/xinclude"
+         xml:id="sec-prefer-remote-fetch">
+ <title>prefer-remote-fetch overlay</title>
+
+ <para>
+  <function>prefer-remote-fetch</function> is an overlay that download sources on remote builder. This is useful when the evaluating machine has a slow upload while the builder can fetch faster directly from the source. To use it, put the following snippet as a new overlay:
+<programlisting>
+self: super:
+  (super.prefer-remote-fetch self super)
+</programlisting>
+  A full configuration example for that sets the overlay up for your own account, could look like this
+<screen>
+<prompt>$ </prompt>mkdir ~/.config/nixpkgs/overlays/
+<prompt>$ </prompt>cat &gt; ~/.config/nixpkgs/overlays/prefer-remote-fetch.nix &lt;&lt;EOF
+  self: super: super.prefer-remote-fetch self super
+EOF
+</screen>
+ </para>
+</section>

sources/nixpkgs/doc/languages-frameworks/android.section.md

@@ -0,0 +1,239 @@
+---
+title: Android
+author: Sander van der Burg
+date: 2018-11-18
+---
+# Android
+
+The Android build environment provides three major features and a number of
+supporting features.
+
+Deploying an Android SDK installation with plugins
+--------------------------------------------------
+The first use case is deploying the SDK with a desired set of plugins or subsets
+of an SDK.
+
+```nix
+with import <nixpkgs> {};
+
+let
+  androidComposition = androidenv.composeAndroidPackages {
+    toolsVersion = "25.2.5";
+    platformToolsVersion = "27.0.1";
+    buildToolsVersions = [ "27.0.3" ];
+    includeEmulator = false;
+    emulatorVersion = "27.2.0";
+    platformVersions = [ "24" ];
+    includeSources = false;
+    includeDocs = false;
+    includeSystemImages = false;
+    systemImageTypes = [ "default" ];
+    abiVersions = [ "armeabi-v7a" ];
+    lldbVersions = [ "2.0.2558144" ];
+    cmakeVersions = [ "3.6.4111459" ];
+    includeNDK = false;
+    ndkVersion = "16.1.4479499";
+    useGoogleAPIs = false;
+    useGoogleTVAddOns = false;
+    includeExtras = [
+      "extras;google;gcm"
+    ];
+  };
+in
+androidComposition.androidsdk
+```
+
+The above function invocation states that we want an Android SDK with the above
+specified plugin versions. By default, most plugins are disabled. Notable
+exceptions are the tools, platform-tools and build-tools sub packages.
+
+The following parameters are supported:
+
+* `toolsVersion`, specifies the version of the tools package to use
+* `platformsToolsVersion` specifies the version of the `platform-tools` plugin
+* `buildToolsVersion` specifies the versions of the `build-tools` plugins to
+  use.
+* `includeEmulator` specifies whether to deploy the emulator package (`false`
+  by default). When enabled, the version of the emulator to deploy can be
+  specified by setting the `emulatorVersion` parameter.
+* `includeDocs` specifies whether the documentation catalog should be included.
+* `lldbVersions` specifies what LLDB versions should be deployed.
+* `cmakeVersions` specifies which CMake versions should be deployed.
+* `includeNDK` specifies that the Android NDK bundle should be included.
+  Defaults to: `false`.
+* `ndkVersion` specifies the NDK version that we want to use.
+* `includeExtras` is an array of identifier strings referring to arbitrary
+  add-on packages that should be installed.
+* `platformVersions` specifies which platform SDK versions should be included.
+
+For each platform version that has been specified, we can apply the following
+options:
+
+* `includeSystemImages` specifies whether a system image for each platform SDK
+  should be included.
+* `includeSources` specifies whether the sources for each SDK version should be
+  included.
+* `useGoogleAPIs` specifies that for each selected platform version the
+  Google API should be included.
+* `useGoogleTVAddOns` specifies that for each selected platform version the
+  Google TV add-on should be included.
+
+For each requested system image we can specify the following options:
+
+* `systemImageTypes` specifies what kind of system images should be included.
+  Defaults to: `default`.
+* `abiVersions` specifies what kind of ABI version of each system image should
+  be included. Defaults to: `armeabi-v7a`.
+
+Most of the function arguments have reasonable default settings.
+
+When building the above expression with:
+
+```bash
+$ nix-build
+```
+
+The Android SDK gets deployed with all desired plugin versions.
+
+We can also deploy subsets of the Android SDK. For example, to only the
+`platform-tools` package, you can evaluate the following expression:
+
+```nix
+with import <nixpkgs> {};
+
+let
+  androidComposition = androidenv.composeAndroidPackages {
+    # ...
+  };
+in
+androidComposition.platform-tools
+```
+
+Using predefine Android package compositions
+--------------------------------------------
+In addition to composing an Android package set manually, it is also possible
+to use a predefined composition that contains all basic packages for a specific
+Android version, such as version 9.0 (API-level 28).
+
+The following Nix expression can be used to deploy the entire SDK with all basic
+plugins:
+
+```nix
+with import <nixpkgs> {};
+
+androidenv.androidPkgs_9_0.androidsdk
+```
+
+It is also possible to use one plugin only:
+
+```nix
+with import <nixpkgs> {};
+
+androidenv.androidPkgs_9_0.platform-tools
+```
+
+Building an Android application
+-------------------------------
+In addition to the SDK, it is also possible to build an Ant-based Android
+project and automatically deploy all the Android plugins that a project
+requires.
+
+```nix
+with import <nixpkgs> {};
+
+androidenv.buildApp {
+  name = "MyAndroidApp";
+  src = ./myappsources;
+  release = true;
+
+  # If release is set to true, you need to specify the following parameters
+  keyStore = ./keystore;
+  keyAlias = "myfirstapp";
+  keyStorePassword = "mykeystore";
+  keyAliasPassword = "myfirstapp";
+
+  # Any Android SDK parameters that install all the relevant plugins that a
+  # build requires
+  platformVersions = [ "24" ];
+
+  # When we include the NDK, then ndk-build is invoked before Ant gets invoked
+  includeNDK = true;
+}
+```
+
+Aside from the app-specific build parameters (`name`, `src`, `release` and
+keystore parameters), the `buildApp {}` function supports all the function
+parameters that the SDK composition function (the function shown in the
+previous section) supports.
+
+This build function is particularly useful when it is desired to use
+[Hydra](http://nixos.org/hydra): the Nix-based continuous integration solution
+to build Android apps. An Android APK gets exposed as a build product and can be
+installed on any Android device with a web browser by navigating to the build
+result page.
+
+Spawning emulator instances
+---------------------------
+For testing purposes, it can also be quite convenient to automatically generate
+scripts that spawn emulator instances with all desired configuration settings.
+
+An emulator spawn script can be configured by invoking the `emulateApp {}`
+function:
+
+```nix
+with import <nixpkgs> {};
+
+androidenv.emulateApp {
+  name = "emulate-MyAndroidApp";
+  platformVersion = "28";
+  abiVersion = "x86_64"; # armeabi-v7a, mips, x86
+  systemImageType = "google_apis_playstore";
+}
+```
+
+It is also possible to specify an APK to deploy inside the emulator
+and the package and activity names to launch it:
+
+```nix
+with import <nixpkgs> {};
+
+androidenv.emulateApp {
+  name = "emulate-MyAndroidApp";
+  platformVersion = "24";
+  abiVersion = "armeabi-v7a"; # mips, x86, x86_64
+  systemImageType = "default";
+  useGoogleAPIs = false;
+  app = ./MyApp.apk;
+  package = "MyApp";
+  activity = "MainActivity";
+}
+```
+
+In addition to prebuilt APKs, you can also bind the APK parameter to a
+`buildApp {}` function invocation shown in the previous example.
+
+Querying the available versions of each plugin
+----------------------------------------------
+When using any of the previously shown functions, it may be a bit inconvenient
+to find out what options are supported, since the Android SDK provides many
+plugins.
+
+A shell script in the `pkgs/development/mobile/androidenv/` sub directory can be used to retrieve all
+possible options:
+
+```bash
+sh ./querypackages.sh packages build-tools
+```
+
+The above command-line instruction queries all build-tools versions in the
+generated `packages.nix` expression.
+
+Updating the generated expressions
+----------------------------------
+Most of the Nix expressions are generated from XML files that the Android
+package manager uses. To update the expressions run the `generate.sh` script
+that is stored in the `pkgs/development/mobile/androidenv/` sub directory:
+
+```bash
+sh ./generate.sh
+```

sources/nixpkgs/doc/languages-frameworks/beam.xml

@@ -0,0 +1,159 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-beam">
+ <title>BEAM Languages (Erlang, Elixir &amp; LFE)</title>
+
+ <section xml:id="beam-introduction">
+  <title>Introduction</title>
+
+  <para>
+   In this document and related Nix expressions, we use the term, <emphasis>BEAM</emphasis>, to describe the environment. BEAM is the name of the Erlang Virtual Machine and, as far as we're concerned, from a packaging perspective, all languages that run on the BEAM are interchangeable. That which varies, like the build system, is transparent to users of any given BEAM package, so we make no distinction.
+  </para>
+ </section>
+
+ <section xml:id="beam-structure">
+  <title>Structure</title>
+
+  <para>
+   All BEAM-related expressions are available via the top-level <literal>beam</literal> attribute, which includes:
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     <literal>interpreters</literal>: a set of compilers running on the BEAM, including multiple Erlang/OTP versions (<literal>beam.interpreters.erlangR19</literal>, etc), Elixir (<literal>beam.interpreters.elixir</literal>) and LFE (<literal>beam.interpreters.lfe</literal>).
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     <literal>packages</literal>: a set of package builders (Mix and rebar3), each compiled with a specific Erlang/OTP version, e.g. <literal>beam.packages.erlangR19</literal>.
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <para>
+   The default Erlang compiler, defined by <literal>beam.interpreters.erlang</literal>, is aliased as <literal>erlang</literal>. The default BEAM package set is defined by <literal>beam.packages.erlang</literal> and aliased at the top level as <literal>beamPackages</literal>.
+  </para>
+
+  <para>
+   To create a package builder built with a custom Erlang version, use the lambda, <literal>beam.packagesWith</literal>, which accepts an Erlang/OTP derivation and produces a package builder similar to <literal>beam.packages.erlang</literal>.
+  </para>
+
+  <para>
+   Many Erlang/OTP distributions available in <literal>beam.interpreters</literal> have versions with ODBC and/or Java enabled or without wx (no observer support). For example, there's <literal>beam.interpreters.erlangR22_odbc_javac</literal>, which corresponds to <literal>beam.interpreters.erlangR22</literal> and <literal>beam.interpreters.erlangR22_nox</literal>, which corresponds to <literal>beam.interpreters.erlangR22</literal>.
+  </para>
+ </section>
+
+ <section xml:id="build-tools">
+  <title>Build Tools</title>
+
+  <section xml:id="build-tools-rebar3">
+   <title>Rebar3</title>
+
+   <para>
+    We provide a version of Rebar3, under <literal>rebar3</literal>. We also provide a helper to fetch Rebar3 dependencies from a lockfile under <literal>fetchRebar3Deps</literal>.
+   </para>
+  </section>
+
+  <section xml:id="build-tools-other">
+   <title>Mix &amp; Erlang.mk</title>
+
+   <para>
+    Both Mix and Erlang.mk work exactly as expected. There is a bootstrap process that needs to be run for both, however, which is supported by the <literal>buildMix</literal> and <literal>buildErlangMk</literal> derivations, respectively.
+   </para>
+  </section>
+ </section>
+
+ <section xml:id="how-to-install-beam-packages">
+  <title>How to Install BEAM Packages</title>
+
+  <para>
+   BEAM builders are not registered at the top level, simply because they are not relevant to the vast majority of Nix users. 
+   To install any of those builders into your profile, refer to them by their attribute path <literal>beamPackages.rebar3</literal>:
+  </para>
+
+  <screen>
+  <prompt>$ </prompt>nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.rebar3
+  </screen>
+</section>
+
+ <section xml:id="packaging-beam-applications">
+  <title>Packaging BEAM Applications</title>
+
+  <section  xml:id="packaging-erlang-applications">
+   <title>Erlang Applications</title>
+
+   <section xml:id="rebar3-packages">
+    <title>Rebar3 Packages</title>
+
+    <para>
+     The Nix function, <literal>buildRebar3</literal>, defined in <literal>beam.packages.erlang.buildRebar3</literal> and aliased at the top level, can be used to build a derivation that understands how to build a Rebar3 project.
+    </para>
+
+    <para>
+     If a package needs to compile native code via Rebar3's port compilation mechanism, add <literal>compilePort = true;</literal> to the derivation.
+    </para>
+   </section>
+
+   <section xml:id="erlang-mk-packages">
+    <title>Erlang.mk Packages</title>
+
+    <para>
+     Erlang.mk functions similarly to Rebar3, except we use <literal>buildErlangMk</literal> instead of <literal>buildRebar3</literal>.
+    </para>
+
+   </section>
+
+   <section xml:id="mix-packages">
+    <title>Mix Packages</title>
+
+    <para>
+     Mix functions similarly to Rebar3, except we use <literal>buildMix</literal> instead of <literal>buildRebar3</literal>.
+    </para>
+
+    <para>
+     Alternatively, we can use <literal>buildHex</literal> as a shortcut:
+    </para>
+   </section>
+  </section>
+ </section>
+
+ <section xml:id="how-to-develop">
+  <title>How to Develop</title>
+
+  <section xml:id="creating-a-shell">
+   <title>Creating a Shell</title>
+
+  <para>
+    Usually, we need to create a <literal>shell.nix</literal> file and do our development inside of the environment specified therein. Just install your version of erlang and other interpreter, and then user your normal build tools.
+    As an example with elixir:
+  </para>
+
+<programlisting>
+{ pkgs ? import &quot;&lt;nixpkgs&quot;&gt; {} }:
+
+with pkgs;
+
+let
+
+  elixir = beam.packages.erlangR22.elixir_1_9;
+
+in
+mkShell {
+  buildInputs = [ elixir ];
+
+  ERL_INCLUDE_PATH="${erlang}/lib/erlang/usr/include";
+}
+</programlisting>
+
+   <section xml:id="building-in-a-shell">
+    <title>Building in a Shell (for Mix Projects)</title>
+
+    <para>
+     Using a <literal>shell.nix</literal> as described (see <xref
+      linkend="creating-a-shell"/>) should just work.
+    </para>
+   </section>
+  </section>
+ </section>
+</section>

sources/nixpkgs/doc/languages-frameworks/bower.xml

@@ -0,0 +1,196 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-bower">
+ <title>Bower</title>
+
+ <para>
+  <link xlink:href="http://bower.io">Bower</link> is a package manager for web site front-end components. Bower packages (comprising of build artefacts and sometimes sources) are stored in <command>git</command> repositories, typically on Github. The package registry is run by the Bower team with package metadata coming from the <filename>bower.json</filename> file within each package.
+ </para>
+
+ <para>
+  The end result of running Bower is a <filename>bower_components</filename> directory which can be included in the web app's build process.
+ </para>
+
+ <para>
+  Bower can be run interactively, by installing <varname>nodePackages.bower</varname>. More interestingly, the Bower components can be declared in a Nix derivation, with the help of <varname>nodePackages.bower2nix</varname>.
+ </para>
+
+ <section xml:id="ssec-bower2nix-usage">
+  <title><command>bower2nix</command> usage</title>
+
+  <para>
+   Suppose you have a <filename>bower.json</filename> with the following contents:
+   <example xml:id="ex-bowerJson">
+    <title><filename>bower.json</filename></title>
+<programlisting language="json">
+<![CDATA[{
+  "name": "my-web-app",
+  "dependencies": {
+    "angular": "~1.5.0",
+    "bootstrap": "~3.3.6"
+  }
+}]]>
+</programlisting>
+   </example>
+  </para>
+
+  <para>
+   Running <command>bower2nix</command> will produce something like the following output:
+<programlisting language="nix">
+<![CDATA[{ fetchbower, buildEnv }:
+buildEnv { name = "bower-env"; ignoreCollisions = true; paths = [
+  (fetchbower "angular" "1.5.3" "~1.5.0" "1749xb0firxdra4rzadm4q9x90v6pzkbd7xmcyjk6qfza09ykk9y")
+  (fetchbower "bootstrap" "3.3.6" "~3.3.6" "1vvqlpbfcy0k5pncfjaiskj3y6scwifxygfqnw393sjfxiviwmbv")
+  (fetchbower "jquery" "2.2.2" "1.9.1 - 2" "10sp5h98sqwk90y4k6hbdviwqzvzwqf47r3r51pakch5ii2y7js1")
+]; }]]>
+</programlisting>
+  </para>
+
+  <para>
+   Using the <command>bower2nix</command> command line arguments, the output can be redirected to a file. A name like <filename>bower-packages.nix</filename> would be fine.
+  </para>
+
+  <para>
+   The resulting derivation is a union of all the downloaded Bower packages (and their dependencies). To use it, they still need to be linked together by Bower, which is where <varname>buildBowerComponents</varname> is useful.
+  </para>
+ </section>
+
+ <section xml:id="ssec-build-bower-components">
+  <title><varname>buildBowerComponents</varname> function</title>
+
+  <para>
+   The function is implemented in <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/bower-modules/generic/default.nix"> <filename>pkgs/development/bower-modules/generic/default.nix</filename></link>. Example usage:
+   <example xml:id="ex-buildBowerComponents">
+    <title>buildBowerComponents</title>
+<programlisting language="nix">
+bowerComponents = buildBowerComponents {
+  name = "my-web-app";
+  generated = ./bower-packages.nix; <co xml:id="ex-buildBowerComponents-1" />
+  src = myWebApp; <co xml:id="ex-buildBowerComponents-2" />
+};
+</programlisting>
+   </example>
+  </para>
+
+  <para>
+   In <xref linkend="ex-buildBowerComponents" />, the following arguments are of special significance to the function:
+   <calloutlist>
+    <callout arearefs="ex-buildBowerComponents-1">
+     <para>
+      <varname>generated</varname> specifies the file which was created by <command>bower2nix</command>.
+     </para>
+    </callout>
+    <callout arearefs="ex-buildBowerComponents-2">
+     <para>
+      <varname>src</varname> is your project's sources. It needs to contain a <filename>bower.json</filename> file.
+     </para>
+    </callout>
+   </calloutlist>
+  </para>
+
+  <para>
+   <varname>buildBowerComponents</varname> will run Bower to link together the output of <command>bower2nix</command>, resulting in a <filename>bower_components</filename> directory which can be used.
+  </para>
+
+  <para>
+   Here is an example of a web frontend build process using <command>gulp</command>. You might use <command>grunt</command>, or anything else.
+  </para>
+
+  <example xml:id="ex-bowerGulpFile">
+   <title>Example build script (<filename>gulpfile.js</filename>)</title>
+<programlisting language="javascript">
+<![CDATA[var gulp = require('gulp');
+
+gulp.task('default', [], function () {
+  gulp.start('build');
+});
+
+gulp.task('build', [], function () {
+  console.log("Just a dummy gulp build");
+  gulp
+    .src(["./bower_components/**/*"])
+    .pipe(gulp.dest("./gulpdist/"));
+});]]>
+</programlisting>
+  </example>
+
+  <example xml:id="ex-buildBowerComponentsDefaultNix">
+   <title>Full example — <filename>default.nix</filename></title>
+<programlisting language="nix">
+{ myWebApp ? { outPath = ./.; name = "myWebApp"; }
+, pkgs ? import &lt;nixpkgs&gt; {}
+}:
+
+pkgs.stdenv.mkDerivation {
+  name = "my-web-app-frontend";
+  src = myWebApp;
+
+  buildInputs = [ pkgs.nodePackages.gulp ];
+
+  bowerComponents = pkgs.buildBowerComponents { <co xml:id="ex-buildBowerComponentsDefault-1" />
+    name = "my-web-app";
+    generated = ./bower-packages.nix;
+    src = myWebApp;
+  };
+
+  buildPhase = ''
+    cp --reflink=auto --no-preserve=mode -R $bowerComponents/bower_components . <co xml:id="ex-buildBowerComponentsDefault-2" />
+    export HOME=$PWD <co xml:id="ex-buildBowerComponentsDefault-3" />
+    ${pkgs.nodePackages.gulp}/bin/gulp build <co xml:id="ex-buildBowerComponentsDefault-4" />
+  '';
+
+  installPhase = "mv gulpdist $out";
+}
+</programlisting>
+  </example>
+
+  <para>
+   A few notes about <xref linkend="ex-buildBowerComponentsDefaultNix" />:
+   <calloutlist>
+    <callout arearefs="ex-buildBowerComponentsDefault-1">
+     <para>
+      The result of <varname>buildBowerComponents</varname> is an input to the frontend build.
+     </para>
+    </callout>
+    <callout arearefs="ex-buildBowerComponentsDefault-2">
+     <para>
+      Whether to symlink or copy the <filename>bower_components</filename> directory depends on the build tool in use. In this case a copy is used to avoid <command>gulp</command> silliness with permissions.
+     </para>
+    </callout>
+    <callout arearefs="ex-buildBowerComponentsDefault-3">
+     <para>
+      <command>gulp</command> requires <varname>HOME</varname> to refer to a writeable directory.
+     </para>
+    </callout>
+    <callout arearefs="ex-buildBowerComponentsDefault-4">
+     <para>
+      The actual build command. Other tools could be used.
+     </para>
+    </callout>
+   </calloutlist>
+  </para>
+ </section>
+
+ <section xml:id="ssec-bower2nix-troubleshooting">
+  <title>Troubleshooting</title>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <literal>ENOCACHE</literal> errors from <varname>buildBowerComponents</varname>
+    </term>
+    <listitem>
+     <para>
+      This means that Bower was looking for a package version which doesn't exist in the generated <filename>bower-packages.nix</filename>.
+     </para>
+     <para>
+      If <filename>bower.json</filename> has been updated, then run <command>bower2nix</command> again.
+     </para>
+     <para>
+      It could also be a bug in <command>bower2nix</command> or <command>fetchbower</command>. If possible, try reformulating the version specification in <filename>bower.json</filename>.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+ </section>
+</section>

sources/nixpkgs/doc/languages-frameworks/coq.xml

@@ -0,0 +1,52 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-coq">
+ <title>Coq</title>
+
+ <para>
+  Coq libraries should be installed in <literal>$(out)/lib/coq/${coq.coq-version}/user-contrib/</literal>. Such directories are automatically added to the <literal>$COQPATH</literal> environment variable by the hook defined in the Coq derivation.
+ </para>
+
+ <para>
+  Some extensions (plugins) might require OCaml and sometimes other OCaml packages. The <literal>coq.ocamlPackages</literal> attribute can be used to depend on the same package set Coq was built against.
+ </para>
+
+ <para>
+  Coq libraries may be compatible with some specific versions of Coq only. The <literal>compatibleCoqVersions</literal> attribute is used to precisely select those versions of Coq that are compatible with this derivation.
+ </para>
+
+ <para>
+  Here is a simple package example. It is a pure Coq library, thus it depends on Coq. It builds on the Mathematical Components library, thus it also takes <literal>mathcomp</literal> as <literal>buildInputs</literal>. Its <literal>Makefile</literal> has been generated using <literal>coq_makefile</literal> so we only have to set the <literal>$COQLIB</literal> variable at install time.
+ </para>
+
+<programlisting>
+{ stdenv, fetchFromGitHub, coq, mathcomp }:
+
+stdenv.mkDerivation rec {
+  name = "coq${coq.coq-version}-multinomials-${version}";
+  version = "1.0";
+  src = fetchFromGitHub {
+    owner = "math-comp";
+    repo = "multinomials";
+    rev = version;
+    sha256 = "1qmbxp1h81cy3imh627pznmng0kvv37k4hrwi2faa101s6bcx55m";
+  };
+
+  buildInputs = [ coq ];
+  propagatedBuildInputs = [ mathcomp ];
+
+  installFlags = "COQLIB=$(out)/lib/coq/${coq.coq-version}/";
+
+  meta = {
+    description = "A Coq/SSReflect Library for Monoidal Rings and Multinomials";
+    inherit (src.meta) homepage;
+    license = stdenv.lib.licenses.cecill-b;
+    inherit (coq.meta) platforms;
+  };
+
+  passthru = {
+    compatibleCoqVersions = v: builtins.elem v [ "8.5" "8.6" "8.7" ];
+  };
+}
+</programlisting>
+</section>

sources/nixpkgs/doc/languages-frameworks/crystal.section.md

@@ -0,0 +1,71 @@
+# Crystal
+
+## Building a Crystal package
+
+This section uses [Mint](https://github.com/mint-lang/mint) as an example for how to build a Crystal package.
+
+If the Crystal project has any dependencies, the first step is to get a `shards.nix` file encoding those. Get a copy of the project and go to its root directory such that its `shard.lock` file is in the current directory, then run `crystal2nix` in it
+```bash
+$ git clone https://github.com/mint-lang/mint
+$ cd mint
+$ git checkout 0.5.0
+$ nix-shell -p crystal2nix --run crystal2nix
+```
+
+This should have generated a `shards.nix` file.
+
+Next create a Nix file for your derivation and use `pkgs.crystal.buildCrystalPackage` as follows:
+```nix
+with import <nixpkgs> {};
+crystal.buildCrystalPackage rec {
+  pname = "mint";
+  version = "0.5.0";
+
+  src = fetchFromGitHub {
+    owner = "mint-lang";
+    repo = "mint";
+    rev = version;
+    sha256 = "0vxbx38c390rd2ysvbwgh89v2232sh5rbsp3nk9wzb70jybpslvl";
+  };
+
+  # Insert the path to your shards.nix file here
+  shardsFile = ./shards.nix;
+
+  ...
+}
+```
+
+This won't build anything yet, because we haven't told it what files build. We can specify a mapping from binary names to source files with the `crystalBinaries` attribute. The project's compilation instructions should show this. For Mint, the binary is called "mint", which is compiled from the source file `src/mint.cr`, so we'll specify this as follows:
+
+```nix
+  crystalBinaries.mint.src = "src/mint.cr";
+
+  # ...
+```
+
+Additionally you can override the default `crystal build` options (which are currently `--release --progress --no-debug --verbose`) with
+
+```nix
+  crystalBinaries.mint.options = [ "--release" "--verbose" ];
+```
+
+Depending on the project, you might need additional steps to get it to compile successfully. In Mint's case, we need to link against openssl, so in the end the Nix file looks as follows:
+
+```nix
+with import <nixpkgs> {};
+crystal.buildCrystalPackage rec {
+  version = "0.5.0";
+  pname = "mint";
+  src = fetchFromGitHub {
+    owner = "mint-lang";
+    repo = "mint";
+    rev = version;
+    sha256 = "0vxbx38c390rd2ysvbwgh89v2232sh5rbsp3nk9wzb70jybpslvl";
+  };
+
+  shardsFile = ./shards.nix;
+  crystalBinaries.mint.src = "src/mint.cr";
+
+  buildInputs = [ openssl_1_0_2 ];
+}
+```

sources/nixpkgs/doc/languages-frameworks/emscripten.section.md

@@ -0,0 +1,185 @@
+# Emscripten
+
+[Emscripten](https://github.com/kripken/emscripten): An LLVM-to-JavaScript Compiler
+
+This section of the manual covers how to use `emscripten` in nixpkgs.
+
+Minimal requirements:
+
+* nix
+* nixpkgs
+
+Modes of use of `emscripten`:
+
+* **Imperative usage** (on the command line):
+
+   If you want to work with `emcc`, `emconfigure` and `emmake` as you are used to from Ubuntu and similar distributions you can use these commands:
+
+    * `nix-env -i emscripten`
+    * `nix-shell -p emscripten`
+
+* **Declarative usage**:
+
+    This mode is far more power full since this makes use of `nix` for dependency management of emscripten libraries and targets by using the `mkDerivation` which is implemented by `pkgs.emscriptenStdenv` and `pkgs.buildEmscriptenPackage`. The source for the packages is in `pkgs/top-level/emscripten-packages.nix` and the abstraction behind it in `pkgs/development/em-modules/generic/default.nix`.
+    * build and install all packages: 
+        * `nix-env -iA emscriptenPackages` 
+          
+    * dev-shell for zlib implementation hacking: 
+        * `nix-shell -A emscriptenPackages.zlib` 
+
+
+## Imperative usage
+
+A few things to note:
+
+* `export EMCC_DEBUG=2` is nice for debugging
+* `~/.emscripten`, the build artifact cache sometimes creates issues and needs to be removed from time to time
+
+
+## Declarative usage
+
+Let's see two different examples from `pkgs/top-level/emscripten-packages.nix`:
+
+* `pkgs.zlib.override`
+* `pkgs.buildEmscriptenPackage`
+
+Both are interesting concepts.
+
+A special requirement of the `pkgs.buildEmscriptenPackage` is the `doCheck = true` is a default meaning that each emscriptenPackage requires a `checkPhase` implemented.
+
+* Use `export EMCC_DEBUG=2` from within a emscriptenPackage's `phase` to get more detailed debug output what is going wrong.
+* ~/.emscripten cache is requiring us to set `HOME=$TMPDIR` in individual phases. This makes compilation slower but also makes it more deterministic.
+
+### Usage 1: pkgs.zlib.override
+
+This example uses `zlib` from nixpkgs but instead of compiling **C** to **ELF** it compiles **C** to **JS** since we were using `pkgs.zlib.override` and changed stdenv to `pkgs.emscriptenStdenv`. A few adaptions and hacks were set in place to make it working. One advantage is that when `pkgs.zlib` is updated, it will automatically update this package as well. However, this can also be the downside...
+
+See the `zlib` example:
+
+    zlib = (pkgs.zlib.override {
+      stdenv = pkgs.emscriptenStdenv;
+    }).overrideDerivation
+    (old: rec {
+      buildInputs = old.buildInputs ++ [ pkgconfig ];
+      # we need to reset this setting!
+      NIX_CFLAGS_COMPILE="";
+      configurePhase = ''
+        # FIXME: Some tests require writing at $HOME
+        HOME=$TMPDIR
+        runHook preConfigure
+
+        #export EMCC_DEBUG=2
+        emconfigure ./configure --prefix=$out --shared
+
+        runHook postConfigure
+      '';
+      dontStrip = true;
+      outputs = [ "out" ];
+      buildPhase = ''
+        emmake make
+      '';
+      installPhase = ''
+        emmake make install
+      '';
+      checkPhase = ''
+        echo "================= testing zlib using node ================="
+
+        echo "Compiling a custom test"
+        set -x
+        emcc -O2 -s EMULATE_FUNCTION_POINTER_CASTS=1 test/example.c -DZ_SOLO \
+        libz.so.${old.version} -I . -o example.js
+
+        echo "Using node to execute the test"
+        ${pkgs.nodejs}/bin/node ./example.js 
+
+        set +x
+        if [ $? -ne 0 ]; then
+          echo "test failed for some reason"
+          exit 1;
+        else
+          echo "it seems to work! very good."
+        fi
+        echo "================= /testing zlib using node ================="
+      '';
+
+      postPatch = pkgs.stdenv.lib.optionalString pkgs.stdenv.isDarwin ''
+        substituteInPlace configure \
+          --replace '/usr/bin/libtool' 'ar' \
+          --replace 'AR="libtool"' 'AR="ar"' \
+          --replace 'ARFLAGS="-o"' 'ARFLAGS="-r"'
+      '';
+    });
+
+### Usage 2: pkgs.buildEmscriptenPackage
+
+This `xmlmirror` example features a emscriptenPackage which is defined completely from this context and no `pkgs.zlib.override` is used. 
+
+    xmlmirror = pkgs.buildEmscriptenPackage rec {
+      name = "xmlmirror";
+
+      buildInputs = [ pkgconfig autoconf automake libtool gnumake libxml2 nodejs openjdk json_c ];
+      nativeBuildInputs = [ pkgconfig zlib ];
+
+      src = pkgs.fetchgit {
+        url = "https://gitlab.com/odfplugfest/xmlmirror.git";
+        rev = "4fd7e86f7c9526b8f4c1733e5c8b45175860a8fd";
+        sha256 = "1jasdqnbdnb83wbcnyrp32f36w3xwhwp0wq8lwwmhqagxrij1r4b";
+      };
+
+      configurePhase = ''
+        rm -f fastXmlLint.js*
+        # a fix for ERROR:root:For asm.js, TOTAL_MEMORY must be a multiple of 16MB, was 234217728
+        # https://gitlab.com/odfplugfest/xmlmirror/issues/8
+        sed -e "s/TOTAL_MEMORY=234217728/TOTAL_MEMORY=268435456/g" -i Makefile.emEnv
+        # https://github.com/kripken/emscripten/issues/6344
+        # https://gitlab.com/odfplugfest/xmlmirror/issues/9
+        sed -e "s/\$(JSONC_LDFLAGS) \$(ZLIB_LDFLAGS) \$(LIBXML20_LDFLAGS)/\$(JSONC_LDFLAGS) \$(LIBXML20_LDFLAGS) \$(ZLIB_LDFLAGS) /g" -i Makefile.emEnv
+        # https://gitlab.com/odfplugfest/xmlmirror/issues/11
+        sed -e "s/-o fastXmlLint.js/-s EXTRA_EXPORTED_RUNTIME_METHODS='[\"ccall\", \"cwrap\"]' -o fastXmlLint.js/g" -i Makefile.emEnv
+      '';
+
+      buildPhase = ''
+        HOME=$TMPDIR
+        make -f Makefile.emEnv
+      '';
+
+      outputs = [ "out" "doc" ];
+
+      installPhase = ''
+        mkdir -p $out/share
+        mkdir -p $doc/share/${name}
+
+        cp Demo* $out/share
+        cp -R codemirror-5.12 $out/share
+        cp fastXmlLint.js* $out/share
+        cp *.xsd $out/share
+        cp *.js $out/share
+        cp *.xhtml $out/share
+        cp *.html $out/share
+        cp *.json $out/share
+        cp *.rng $out/share
+        cp README.md $doc/share/${name}
+      '';
+      checkPhase = ''
+
+      '';
+    }; 
+
+### Declarative debugging
+
+Use `nix-shell -I nixpkgs=/some/dir/nixpkgs -A emscriptenPackages.libz` and from there you can go trough the individual steps. This makes it easy to build a good `unit test` or list the files of the project.
+
+1. `nix-shell -I nixpkgs=/some/dir/nixpkgs -A emscriptenPackages.libz`
+2. `cd /tmp/`
+3. `unpackPhase`
+4. cd libz-1.2.3
+5. `configurePhase`
+6. `buildPhase`
+7. ... happy hacking...
+
+## Summary
+
+Using this toolchain makes it easy to leverage `nix` from NixOS, MacOSX or even Windows (WSL+ubuntu+nix). This toolchain is reproducible, behaves like the rest of the packages from nixpkgs and contains a set of well working examples to learn and adapt from.
+
+If in trouble, ask the maintainers.
+

sources/nixpkgs/doc/languages-frameworks/gnome.xml

@@ -0,0 +1,282 @@
+<section xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xml:id="sec-language-gnome">
+ <title>GNOME</title>
+
+ <section xml:id="ssec-gnome-packaging">
+  <title>Packaging GNOME applications</title>
+
+  <para>
+   Programs in the GNOME universe are written in various languages but they all use GObject-based libraries like GLib, GTK or GStreamer. These libraries are often modular, relying on looking into certain directories to find their modules. However, due to Nix’s specific file system organization, this will fail without our intervention. Fortunately, the libraries usually allow overriding the directories through environment variables, either natively or thanks to a patch in nixpkgs. <link xlink:href="#fun-wrapProgram">Wrapping</link> the executables to ensure correct paths are available to the application constitutes a significant part of packaging a modern desktop application. In this section, we will describe various modules needed by such applications, environment variables needed to make the modules load, and finally a script that will do the work for us.
+  </para>
+
+  <section xml:id="ssec-gnome-settings">
+   <title>Settings</title>
+
+   <para>
+    <link xlink:href="https://developer.gnome.org/gio/stable/GSettings.html">GSettings</link> API is often used for storing settings. GSettings schemas are required, to know the type and other metadata of the stored values. GLib looks for <filename>glib-2.0/schemas/gschemas.compiled</filename> files inside the directories of <envar>XDG_DATA_DIRS</envar>.
+   </para>
+
+   <para>
+    On Linux, GSettings API is implemented using <link xlink:href="https://wiki.gnome.org/Projects/dconf">dconf</link> backend. You will need to add <literal>dconf</literal> GIO module to <envar>GIO_EXTRA_MODULES</envar> variable, otherwise the <literal>memory</literal> backend will be used and the saved settings will not be persistent.
+   </para>
+
+   <para>
+    Last you will need the dconf database D-Bus service itself. You can enable it using <option>programs.dconf.enable</option>.
+   </para>
+
+   <para>
+    Some applications will also require <package>gsettings-desktop-schemas</package> for things like reading proxy configuration or user interface customization. This dependency is often not mentioned by upstream, you should grep for <literal>org.gnome.desktop</literal> and <literal>org.gnome.system</literal> to see if the schemas are needed.
+   </para>
+  </section>
+
+  <section xml:id="ssec-gnome-icons">
+   <title>Icons</title>
+
+   <para>
+    When an application uses icons, an icon theme should be available in <envar>XDG_DATA_DIRS</envar> during runtime. The package for the default, icon-less <link xlink:href="https://www.freedesktop.org/wiki/Software/icon-theme/">hicolor-icon-theme</link> (should be propagated by every icon theme) contains <link linkend="ssec-gnome-hooks-hicolor-icon-theme">a setup hook</link> that will pick up icon themes from <literal>buildInputs</literal> and pass it to our wrapper. Unfortunately, relying on that would mean every user has to download the theme included in the package expression no matter their preference. For that reason, we leave the installation of icon theme on the user. If you use one of the desktop environments, you probably already have an icon theme installed.
+   </para>
+
+   <para>
+    To avoid costly file system access when locating icons, GTK, <link xlink:href="https://woboq.com/blog/qicon-reads-gtk-icon-cache-in-qt57.html">as well as Qt</link>, can rely on <filename>icon-theme.cache</filename> files from the themes’ top-level directories. These files are generated using <command>gtk-update-icon-cache</command>, which is expected to be run whenever an icon is added or removed to an icon theme (typically an application icon into <literal>hicolor</literal> theme) and some programs do indeed run this after icon installation. However, since packages are installed into their own prefix by Nix, this would lead to conflicts. For that reason, <package>gtk3</package> provides a <link xlink:href="#ssec-gnome-hooks-gtk-drop-icon-theme-cache">setup hook</link> that will clean the file from installation. Since most applications only ship their own icon that will be loaded on start-up, it should not affect them too much. On the other hand, icon themes are much larger and more widely used so we need to cache them. Because we recommend installing icon themes globally, we will generate the cache files from all packages in a profile using a NixOS module. You can enable the cache generation using <option>gtk.iconCache.enable</option> option if your desktop environment does not already do that.
+   </para>
+  </section>
+
+  <section xml:id="ssec-gnome-themes">
+   <title>GTK Themes</title>
+
+   <para>
+    Previously, a GTK theme needed to be in <envar>XDG_DATA_DIRS</envar>. This is no longer necessary for most programs since GTK incorporated Adwaita theme. Some programs (for example, those designed for <link xlink:href="https://elementary.io/docs/human-interface-guidelines#human-interface-guidelines">elementary HIG</link>) might require a special theme like <package>pantheon.elementary-gtk-theme</package>.
+   </para>
+  </section>
+
+  <section xml:id="ssec-gnome-typelibs">
+   <title>GObject introspection typelibs</title>
+
+   <para>
+    <link xlink:href="https://wiki.gnome.org/Projects/GObjectIntrospection">GObject introspection</link> allows applications to use C libraries in other languages easily. It does this through <literal>typelib</literal> files searched in <envar>GI_TYPELIB_PATH</envar>.
+   </para>
+  </section>
+
+  <section xml:id="ssec-gnome-plugins">
+   <title>Various plug-ins</title>
+
+   <para>
+    If your application uses <link xlink:href="https://gstreamer.freedesktop.org/">GStreamer</link> or <link xlink:href="https://wiki.gnome.org/Projects/Grilo">Grilo</link>, you should set <envar>GST_PLUGIN_SYSTEM_PATH_1_0</envar> and <envar>GRL_PLUGIN_PATH</envar>, respectively.
+   </para>
+  </section>
+ </section>
+
+ <section xml:id="ssec-gnome-hooks">
+  <title>Onto <package>wrapGAppsHook</package></title>
+
+  <para>
+   Given the requirements above, the package expression would become messy quickly:
+<programlisting>
+preFixup = ''
+  for f in $(find $out/bin/ $out/libexec/ -type f -executable); do
+    wrapProgram "$f" \
+      --prefix GIO_EXTRA_MODULES : "${getLib dconf}/lib/gio/modules" \
+      --prefix XDG_DATA_DIRS : "$out/share" \
+      --prefix XDG_DATA_DIRS : "$out/share/gsettings-schemas/${name}" \
+      --prefix XDG_DATA_DIRS : "${gsettings-desktop-schemas}/share/gsettings-schemas/${gsettings-desktop-schemas.name}" \
+      --prefix XDG_DATA_DIRS : "${hicolor-icon-theme}/share" \
+      --prefix GI_TYPELIB_PATH : "${lib.makeSearchPath "lib/girepository-1.0" [ pango json-glib ]}"
+  done
+'';
+</programlisting>
+   Fortunately, there is <package>wrapGAppsHook</package>, that does the wrapping for us. In particular, it works in conjunction with other setup hooks that will populate the variable:
+   <itemizedlist>
+    <listitem xml:id="ssec-gnome-hooks-wrapgappshook">
+     <para>
+      <package>wrapGAppsHook</package> itself will add the package’s <filename>share</filename> directory to <envar>XDG_DATA_DIRS</envar>.
+     </para>
+    </listitem>
+    <listitem xml:id="ssec-gnome-hooks-glib">
+     <para>
+      <package>glib</package> setup hook will populate <envar>GSETTINGS_SCHEMAS_PATH</envar> and then <package>wrapGAppsHook</package> will prepend it to <envar>XDG_DATA_DIRS</envar>.
+     </para>
+    </listitem>
+    <listitem xml:id="ssec-gnome-hooks-gtk-drop-icon-theme-cache">
+     <para>
+      One of <package>gtk3</package>’s setup hooks will remove <filename>icon-theme.cache</filename> files from package’s icon theme directories to avoid conflicts. Icon theme packages should prevent this with <code>dontDropIconThemeCache = true;</code>.
+     </para>
+    </listitem>
+    <listitem xml:id="ssec-gnome-hooks-dconf">
+     <para>
+      <package>dconf.lib</package> is a dependency of <package>wrapGAppsHook</package>, which then also adds it to the <envar>GIO_EXTRA_MODULES</envar> variable.
+     </para>
+    </listitem>
+    <listitem xml:id="ssec-gnome-hooks-hicolor-icon-theme">
+     <para>
+      <package>hicolor-icon-theme</package>’s setup hook will add icon themes to <envar>XDG_ICON_DIRS</envar> which is prepended to <envar>XDG_DATA_DIRS</envar> by <package>wrapGAppsHook</package>.
+     </para>
+    </listitem>
+    <listitem xml:id="ssec-gnome-hooks-gobject-introspection">
+     <para>
+      <package>gobject-introspection</package> setup hook populates <envar>GI_TYPELIB_PATH</envar> variable with <filename>lib/girepository-1.0</filename> directories of dependencies, which is then added to wrapper by <package>wrapGAppsHook</package>. It also adds <filename>share</filename> directories of dependencies to <envar>XDG_DATA_DIRS</envar>, which is intended to promote GIR files but it also <link xlink:href="https://github.com/NixOS/nixpkgs/issues/32790">pollutes the closures</link> of packages using <package>wrapGAppsHook</package>.
+     </para>
+     <warning>
+      <para>
+       The setup hook <link xlink:href="https://github.com/NixOS/nixpkgs/issues/56943">currently</link> does not work in expressions with <literal>strictDeps</literal> enabled, like Python packages. In those cases, you will need to disable it with <code>strictDeps = false;</code>.
+      </para>
+     </warning>
+    </listitem>
+    <listitem xml:id="ssec-gnome-hooks-gst-grl-plugins">
+     <para>
+      Setup hooks of <package>gst_all_1.gstreamer</package> and <package>gnome3.grilo</package> will populate the <envar>GST_PLUGIN_SYSTEM_PATH_1_0</envar> and <envar>GRL_PLUGIN_PATH</envar> variables, respectively, which will then be added to the wrapper by <literal>wrapGAppsHook</literal>.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+
+  <para>
+   You can also pass additional arguments to <literal>makeWrapper</literal> using <literal>gappsWrapperArgs</literal> in <literal>preFixup</literal> hook:
+<programlisting>
+preFixup = ''
+  gappsWrapperArgs+=(
+    # Thumbnailers
+    --prefix XDG_DATA_DIRS : "${gdk-pixbuf}/share"
+    --prefix XDG_DATA_DIRS : "${librsvg}/share"
+    --prefix XDG_DATA_DIRS : "${shared-mime-info}/share"
+  )
+'';
+</programlisting>
+  </para>
+ </section>
+
+ <section xml:id="ssec-gnome-updating">
+  <title>Updating GNOME packages</title>
+
+  <para>
+   Most GNOME package offer <link linkend="var-passthru-updateScript"><literal>updateScript</literal></link>, it is therefore possible to update to latest source tarball by running <command>nix-shell maintainers/scripts/update.nix --argstr package gnome3.nautilus</command> or even en masse with <command>nix-shell maintainers/scripts/update.nix --argstr path gnome3</command>. Read the package’s <filename>NEWS</filename> file to see what changed.
+  </para>
+ </section>
+
+ <section xml:id="ssec-gnome-common-issues">
+  <title>Frequently encountered issues</title>
+
+  <variablelist>
+   <varlistentry xml:id="ssec-gnome-common-issues-no-schemas">
+    <term>
+     <computeroutput>GLib-GIO-ERROR **: <replaceable>06:04:50.903</replaceable>: No GSettings schemas are installed on the system</computeroutput>
+    </term>
+    <listitem>
+     <para>
+      There are no schemas avalable in <envar>XDG_DATA_DIRS</envar>. Temporarily add a random package containing schemas like <package>gsettings-desktop-schemas</package> to <literal>buildInputs</literal>. <link linkend="ssec-gnome-hooks-glib"><package>glib</package></link> and <link linkend="ssec-gnome-hooks-wrapgappshook"><package>wrapGAppsHook</package></link> setup hooks will take care of making the schemas available to application and you will see the actual missing schemas with the <link linkend="ssec-gnome-common-issues-missing-schema">next error</link>. Or you can try looking through the source code for the actual schemas used.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry xml:id="ssec-gnome-common-issues-missing-schema">
+    <term>
+     <computeroutput>GLib-GIO-ERROR **: <replaceable>06:04:50.903</replaceable>: Settings schema ‘<replaceable>org.gnome.foo</replaceable>’ is not installed</computeroutput>
+    </term>
+    <listitem>
+     <para>
+      Package is missing some GSettings schemas. You can find out the package containing the schema with <command>nix-locate <replaceable>org.gnome.foo</replaceable>.gschema.xml</command> and let the hooks handle the wrapping as <link linkend="ssec-gnome-common-issues-no-schemas">above</link>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry xml:id="ssec-gnome-common-issues-double-wrapped">
+    <term>
+     When using <package>wrapGAppsHook</package> with special derivers you can end up with double wrapped binaries.
+    </term>
+    <listitem>
+     <para>
+      This is because derivers like <function>python.pkgs.buildPythonApplication</function> or <function>qt5.mkDerivation</function> have setup-hooks automatically added that produce wrappers with <package>makeWrapper</package>. The simplest way to workaround that is to disable the <package>wrapGAppsHook</package> automatic wrapping with <code>dontWrapGApps = true;</code> and pass the arguments it intended to pass to <package>makeWrapper</package> to another.
+     </para>
+     <para>
+      In the case of a Python application it could look like:
+<programlisting>
+python3.pkgs.buildPythonApplication {
+  pname = "gnome-music";
+  version = "3.32.2";
+
+  nativeBuildInputs = [
+    wrapGAppsHook
+    gobject-introspection
+    ...
+  ];
+
+  dontWrapGApps = true;
+
+  # Arguments to be passed to `makeWrapper`, only used by buildPython*
+  preFixup = ''
+    makeWrapperArgs+=("''${gappsWrapperArgs[@]}")
+  '';
+}
+</programlisting>
+      And for a QT app like:
+<programlisting>
+mkDerivation {
+  pname = "calibre";
+  version = "3.47.0";
+
+  nativeBuildInputs = [
+    wrapGAppsHook
+    qmake
+    ...
+  ];
+
+  dontWrapGApps = true;
+
+  # Arguments to be passed to `makeWrapper`, only used by qt5’s mkDerivation
+  preFixup = ''
+    qtWrapperArgs+=("''${gappsWrapperArgs[@]}")
+  '';
+}
+</programlisting>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry xml:id="ssec-gnome-common-issues-unwrappable-package">
+    <term>
+     I am packaging a project that cannot be wrapped, like a library or GNOME Shell extension.
+    </term>
+    <listitem>
+     <para>
+      You can rely on applications depending on the library set the necessary environment variables but that it often easy to miss. Instead we recommend to patch the paths in the source code whenever possible. Here are some examples:
+      <itemizedlist>
+       <listitem xml:id="ssec-gnome-common-issues-unwrappable-package-gnome-shell-ext">
+        <para>
+         <link xlink:href="https://github.com/NixOS/nixpkgs/blob/7bb8f05f12ca3cff9da72b56caa2f7472d5732bc/pkgs/desktops/gnome-3/core/gnome-shell-extensions/default.nix#L21-L24">Replacing a <envar>GI_TYPELIB_PATH</envar> in GNOME Shell extension</link> – we are using <function>substituteAll</function> to include the path to a typelib into a patch.
+        </para>
+       </listitem>
+       <listitem xml:id="ssec-gnome-common-issues-unwrappable-package-gsettings">
+        <para>
+         The following examples are hardcoding GSettings schema paths. To get the schema paths we use the functions
+         <itemizedlist>
+          <listitem>
+           <para>
+            <function>glib.getSchemaPath</function> Takes a nix package attribute as an argument.
+           </para>
+          </listitem>
+          <listitem>
+           <para>
+            <function>glib.makeSchemaPath</function> Takes a package output like <literal>$out</literal> and a derivation name. You should use this if the schemas you need to hardcode are in the same derivation.
+           </para>
+          </listitem>
+         </itemizedlist>
+        </para>
+        <para xml:id="ssec-gnome-common-issues-unwrappable-package-gsettings-vala">
+         <link xlink:href="https://github.com/NixOS/nixpkgs/blob/7bb8f05f12ca3cff9da72b56caa2f7472d5732bc/pkgs/desktops/pantheon/apps/elementary-files/default.nix#L78-L86">Hard-coding GSettings schema path in Vala plug-in (dynamically loaded library)</link> – here, <function>substituteAll</function> cannot be used since the schema comes from the same package preventing us from pass its path to the function, probably due to a <link xlink:href="https://github.com/NixOS/nix/issues/1846">Nix bug</link>.
+        </para>
+        <para xml:id="ssec-gnome-common-issues-unwrappable-package-gsettings-c">
+         <link xlink:href="https://github.com/NixOS/nixpkgs/blob/29c120c065d03b000224872251bed93932d42412/pkgs/development/libraries/glib-networking/default.nix#L31-L34">Hard-coding GSettings schema path in C library</link> – nothing special other than using <link xlink:href="https://github.com/NixOS/nixpkgs/pull/67957#issuecomment-527717467">Coccinelle patch</link> to generate the patch itself.
+        </para>
+       </listitem>
+      </itemizedlist>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry xml:id="ssec-gnome-common-issues-weird-location">
+    <term>
+     I need to wrap a binary outside <filename>bin</filename> and <filename>libexec</filename> directories.
+    </term>
+    <listitem>
+     <para>
+      You can manually trigger the wrapping with <function>wrapGApp</function> in <literal>preFixup</literal> phase. It takes a path to a program as a first argument; the remaining arguments are passed directly to <function xlink:href="#fun-wrapProgram">wrapProgram</function> function.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+ </section>
+</section>

sources/nixpkgs/doc/languages-frameworks/go.xml

@@ -0,0 +1,206 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-go">
+ <title>Go</title>
+
+ <section xml:id="ssec-go-modules">
+  <title>Go modules</title>
+
+  <para>
+   The function <varname> buildGoModule </varname> builds Go programs managed with Go modules. It builds a <link xlink:href="https://github.com/golang/go/wiki/Modules">Go modules</link> through a two phase build:
+   <itemizedlist>
+    <listitem>
+     <para>
+      An intermediate fetcher derivation. This derivation will be used to fetch all of the dependencies of the Go module.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      A final derivation will use the output of the intermediate derivation to build the binaries and produce the final output.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+
+  <example xml:id='ex-buildGoModule'>
+   <title>buildGoModule</title>
+<programlisting>
+pet = buildGoModule rec {
+  pname = "pet";
+  version = "0.3.4";
+
+  src = fetchFromGitHub {
+    owner = "knqyf263";
+    repo = "pet";
+    rev = "v${version}";
+    sha256 = "0m2fzpqxk7hrbxsgqplkg7h2p7gv6s1miymv3gvw0cz039skag0s";
+  };
+
+  modSha256 = "1879j77k96684wi554rkjxydrj8g3hpp0kvxz03sd8dmwr3lh83j"; <co xml:id='ex-buildGoModule-1' />
+
+  subPackages = [ "." ]; <co xml:id='ex-buildGoModule-2' />
+
+  meta = with lib; {
+    description = "Simple command-line snippet manager, written in Go";
+    homepage = https://github.com/knqyf263/pet;
+    license = licenses.mit;
+    maintainers = with maintainers; [ kalbasit ];
+    platforms = platforms.linux ++ platforms.darwin;
+  };
+}
+</programlisting>
+  </example>
+
+  <para>
+   <xref linkend='ex-buildGoModule'/> is an example expression using buildGoModule, the following arguments are of special significance to the function:
+   <calloutlist>
+    <callout arearefs='ex-buildGoModule-1'>
+     <para>
+      <varname>modSha256</varname> is the hash of the output of the intermediate fetcher derivation.
+     </para>
+    </callout>
+    <callout arearefs='ex-buildGoModule-2'>
+     <para>
+      <varname>subPackages</varname> limits the builder from building child packages that have not been listed. If <varname>subPackages</varname> is not specified, all child packages will be built.
+     </para>
+    </callout>
+   </calloutlist>
+  </para>
+ </section>
+
+ <section xml:id="ssec-go-legacy">
+  <title>Go legacy</title>
+
+  <para>
+   The function <varname> buildGoPackage </varname> builds legacy Go programs, not supporting Go modules.
+  </para>
+
+  <example xml:id='ex-buildGoPackage'>
+   <title>buildGoPackage</title>
+<programlisting>
+deis = buildGoPackage rec {
+  pname = "deis";
+  version = "1.13.0";
+
+  goPackagePath = "github.com/deis/deis"; <co xml:id='ex-buildGoPackage-1' />
+  subPackages = [ "client" ]; <co xml:id='ex-buildGoPackage-2' />
+
+  src = fetchFromGitHub {
+    owner = "deis";
+    repo = "deis";
+    rev = "v${version}";
+    sha256 = "1qv9lxqx7m18029lj8cw3k7jngvxs4iciwrypdy0gd2nnghc68sw";
+  };
+
+  goDeps = ./deps.nix; <co xml:id='ex-buildGoPackage-3' />
+
+  buildFlags = "--tags release"; <co xml:id='ex-buildGoPackage-4' />
+}
+</programlisting>
+  </example>
+
+  <para>
+   <xref linkend='ex-buildGoPackage'/> is an example expression using buildGoPackage, the following arguments are of special significance to the function:
+   <calloutlist>
+    <callout arearefs='ex-buildGoPackage-1'>
+     <para>
+      <varname>goPackagePath</varname> specifies the package's canonical Go import path.
+     </para>
+    </callout>
+    <callout arearefs='ex-buildGoPackage-2'>
+     <para>
+      <varname>subPackages</varname> limits the builder from building child packages that have not been listed. If <varname>subPackages</varname> is not specified, all child packages will be built.
+     </para>
+     <para>
+      In this example only <literal>github.com/deis/deis/client</literal> will be built.
+     </para>
+    </callout>
+    <callout arearefs='ex-buildGoPackage-3'>
+     <para>
+      <varname>goDeps</varname> is where the Go dependencies of a Go program are listed as a list of package source identified by Go import path. It could be imported as a separate <varname>deps.nix</varname> file for readability. The dependency data structure is described below.
+     </para>
+    </callout>
+    <callout arearefs='ex-buildGoPackage-4'>
+     <para>
+      <varname>buildFlags</varname> is a list of flags passed to the go build command.
+     </para>
+    </callout>
+   </calloutlist>
+  </para>
+
+  <para>
+   The <varname>goDeps</varname> attribute can be imported from a separate <varname>nix</varname> file that defines which Go libraries are needed and should be included in <varname>GOPATH</varname> for <varname>buildPhase</varname>.
+  </para>
+
+  <example xml:id='ex-goDeps'>
+   <title>deps.nix</title>
+<programlisting>
+[ <co xml:id='ex-goDeps-1' />
+  {
+    goPackagePath = "gopkg.in/yaml.v2"; <co xml:id='ex-goDeps-2' />
+    fetch = {
+      type = "git"; <co xml:id='ex-goDeps-3' />
+      url = "https://gopkg.in/yaml.v2";
+      rev = "a83829b6f1293c91addabc89d0571c246397bbf4";
+      sha256 = "1m4dsmk90sbi17571h6pld44zxz7jc4lrnl4f27dpd1l8g5xvjhh";
+    };
+  }
+  {
+    goPackagePath = "github.com/docopt/docopt-go";
+    fetch = {
+      type = "git";
+      url = "https://github.com/docopt/docopt-go";
+      rev = "784ddc588536785e7299f7272f39101f7faccc3f";
+      sha256 = "0wwz48jl9fvl1iknvn9dqr4gfy1qs03gxaikrxxp9gry6773v3sj";
+    };
+  }
+]
+</programlisting>
+  </example>
+
+  <para>
+   <calloutlist>
+    <callout arearefs='ex-goDeps-1'>
+     <para>
+      <varname>goDeps</varname> is a list of Go dependencies.
+     </para>
+    </callout>
+    <callout arearefs='ex-goDeps-2'>
+     <para>
+      <varname>goPackagePath</varname> specifies Go package import path.
+     </para>
+    </callout>
+    <callout arearefs='ex-goDeps-3'>
+     <para>
+      <varname>fetch type</varname> that needs to be used to get package source. If <varname>git</varname> is used there should be <varname>url</varname>, <varname>rev</varname> and <varname>sha256</varname> defined next to it.
+     </para>
+    </callout>
+   </calloutlist>
+  </para>
+
+  <para>
+   To extract dependency information from a Go package in automated way use <link xlink:href="https://github.com/kamilchm/go2nix">go2nix</link>. It can produce complete derivation and <varname>goDeps</varname> file for Go programs.
+  </para>
+
+  <para>
+   <varname>buildGoPackage</varname> produces <xref linkend='chap-multiple-output' xrefstyle="select: title" /> where <varname>bin</varname> includes program binaries. You can test build a Go binary as follows:
+<screen>
+<prompt>$ </prompt>nix-build -A deis.bin
+</screen>
+   or build all outputs with:
+<screen>
+<prompt>$ </prompt>nix-build -A deis.all
+</screen>
+   <varname>bin</varname> output will be installed by default with <varname>nix-env -i</varname> or <varname>systemPackages</varname>.
+  </para>
+
+  <para>
+   You may use Go packages installed into the active Nix profiles by adding the following to your ~/.bashrc:
+<screen>
+for p in $NIX_PROFILES; do
+    GOPATH="$p/share/go:$GOPATH"
+done
+</screen>
+  </para>
+ </section>
+</section>