The standard build environment (stdenv) is now pure on the x86_64-linux and powerpc-linux platforms, just as on i686-linux. (Purity means that building and using the standard environment has no dependencies outside of the Nix store. For instance, it doesn’t require an external C compiler such as /usr/bin/gcc.) Also, the statically linked binaries used in the bootstrap process are now automatically reproducible, making it easy to update the bootstrap tools and to add support for other Linux platforms. See pkgs/stdenv/linux/make-bootstrap-tools.nix for details.

Hook variables in the generic builder are now executed using the eval shell command. This has a major advantage: you can write hooks directly in Nix expressions. For instance, rather than writing a builder like this:

source $stdenv/setup

postInstall=postInstall
postInstall() {
    ln -sf gzip $out/bin/gunzip
    ln -sf gzip $out/bin/zcat
}

genericBuild

(the gzip builder), you can just add this attribute to the derivation:

postInstall = "ln -sf gzip $out/bin/gunzip; ln -sf gzip $out/bin/zcat";

and so a separate build script becomes unnecessary. This should allow us to get rid of most builders in Nixpkgs.

It is now possible to have the generic builder pass arguments to configure and make that contain whitespace. Previously, for example, you could say in a builder,

configureFlags="CFLAGS=-O0"

but not

configureFlags="CFLAGS=-O0 -g"

since the -g would be interpreted as a separate argument to configure. Now you can say

configureFlagsArray=("CFLAGS=-O0 -g")

or similarly

configureFlagsArray=("CFLAGS=-O0 -g" "LDFLAGS=-L/foo -L/bar")

which does the right thing. Idem for makeFlags, installFlags, checkFlags and distFlags.

Unfortunately you can't pass arrays to Bash through the environment, so you can't put the array above in a Nix expression, e.g.,

configureFlagsArray = ["CFLAGS=-O0 -g"];

since it would just be flattened to a since string. However, you can use the inline hooks described above:

preConfigure = "configureFlagsArray=(\"CFLAGS=-O0 -g\")";

The function fetchurl now has support for two different kinds of mirroring of files. First, it has support for content-addressable mirrors. For example, given the fetchurl call

fetchurl {
  url = http://releases.mozilla.org/.../firefox-2.0.0.6-source.tar.bz2;
  sha1 = "eb72f55e4a8bf08e8c6ef227c0ade3d068ba1082";
}

fetchurl will first try to download this file from http://nix.cs.uu.nl/dist/tarballs/sha1/eb72f55e4a8bf08e8c6ef227c0ade3d068ba1082. If that file doesn’t exist, it will try the original URL. In general, the “content-addressed” location is mirror/hash-type/hash. There is currently only one content-addressable mirror (http://nix.cs.uu.nl/dist/tarballs), but more can be specified in the hashedMirrors attribute in pkgs/build-support/fetchurl/mirrors.nix, or by setting the NIX_HASHED_MIRRORS environment variable to a whitespace-separated list of URLs.

Second, fetchurl has support for widely-mirrored distribution sites such as SourceForge or the Linux kernel archives. Given a URL of the form mirror://site/path, it will try to download path from a configurable list of mirrors for site. (This idea was borrowed from Gentoo Linux.) Example:

fetchurl {
  url = mirror://gnu/gcc/gcc-4.2.0/gcc-core-4.2.0.tar.bz2;
  sha256 = "0ykhzxhr8857dr97z0j9wyybfz1kjr71xk457cfapfw5fjas4ny1";
}

Currently site can be sourceforge, gnu and kernel. The list of mirrors is defined in pkgs/build-support/fetchurl/mirrors.nix. You can override the list of mirrors for a particular site by setting the environment variable NIX_MIRRORS_site, e.g.

export NIX_MIRRORS_sourceforge=http://osdn.dl.sourceforge.net/sourceforge/

Important updates:

Major new packages:

pkgs/system/all-packages-generic.nix is gone, we now just have pkgs/top-level/all-packages.nix that contains all available packages. This should cause much less confusion with users. all-packages.nix is a function that by default returns packages for the current platform, but you can override this by specifying a different system argument.

Certain packages in Nixpkgs are now user-configurable through a configuration file, i.e., without having to edit the Nix expressions in Nixpkgs. For instance, the Firefox provided in the Nixpkgs channel is built without the RealPlayer plugin (for legal reasons). Previously, you could easily enable RealPlayer support by editing the call to the Firefox function in all-packages.nix, but such changes are not respected when Firefox is subsequently updated through the Nixpkgs channel.

The Nixpkgs configuration file (found in ~/.nixpkgs/config.nix or through the NIXPKGS_CONFIG environment variable) is an attribute set that contains configuration options that all-packages.nix reads and uses for certain packages. For instance, the following configuration file:

{
  firefox = {
    enableRealPlayer = true;
  };
}

persistently enables RealPlayer support in the Firefox build.

(Actually, firefox.enableRealPlayer is the only configuration option currently available, but more are sure to be added.)

Support for new platforms:

The default compiler is now GCC 4.1.1.

X11 updated to X.org’s X11R7.1.

Notable new packages:

In total there are now around 809 packages in Nixpkgs.

It is now much easier to override the default C compiler and other tools in stdenv for specific packages. all-packages.nix provides two utility functions for this purpose: overrideGCC and overrideInStdenv. Both take a stdenv and return an augmented stdenv; the formed changes the C compiler, and the latter adds additional packages to the front of stdenv’s initial PATH, allowing tools to be overriden.

For instance, the package strategoxt doesn’t build with the GNU Make in stdenv (version 3.81), so we call it with an augmented stdenv that uses GNU Make 3.80:

strategoxt = (import ../development/compilers/strategoxt) {
  inherit fetchurl pkgconfig sdf aterm;
  stdenv = overrideInStdenv stdenv [gnumake380];
};

gnumake380 = ...;

Likewise, there are many packages that don’t compile with the default GCC (4.1.1), but that’s easily fixed:

exult = import ../games/exult {
  inherit fetchurl SDL SDL_mixer zlib libpng unzip;
  stdenv = overrideGCC stdenv gcc34;
};

It has also become much easier to experiment with changes to the stdenv setup script (which notably contains the generic builder). Since edits to pkgs/stdenv/generic/setup.sh trigger a rebuild of everything, this was formerly quite painful. But now stdenv contains a function to “regenerate” stdenv with a different setup script, allowing the use of a different setup script for specific packages:

pkg = import ... {
  stdenv = stdenv.regenerate ./my-setup.sh;
  ...
}

Packages can now have a human-readable description field. Package descriptions are shown by nix-env -qa --description. In addition, they’re shown on the Nixpkgs release page. A description can be added to a package as follows:

stdenv.mkDerivation {
  name = "exult-1.2";
  ...
  meta = {
    description = "A reimplementation of the Ultima VII game engine";
  };
}

The meta attribute is not passed to the builder, so changes to the description do not trigger a rebuild. Additional meta attributes may be defined in the future (such as the URL of the package’s homepage, the license, etc.).

Distribution files have been moved to http://nix.cs.uu.nl/.

The C library on Linux, Glibc, has been updated to version 2.3.6.

The default compiler is now GCC 3.4.5. GCC 4.0.2 is also available.

The old, unofficial Xlibs has been replaced by the official modularised X11 distribution from X.org, i.e., X11R7.0. X11R7.0 consists of 287 (!) packages, all of which are in Nixpkgs though not all have been tested. It is now possible to build a working X server (previously we only had X client libraries). We use a fully Nixified X server on NixOS.

The Sun JDK 5 has been purified, i.e., it doesn’t require any non-Nix components such as /lib/ld-linux.so.2. This means that Java applications such as Eclipse and Azureus can run on NixOS.

Hardware-accelerated OpenGL support, used by games like Quake 3 (which is now built from source).

Improved support for FreeBSD on x86.

Improved Haskell support; e.g., the GHC build is now pure.

Some support for cross-compilation: cross-compiling builds of GCC and Binutils, and cross-compiled builds of the C library uClibc.

Notable new packages:

Adobe Reader 7.0

Various security updates (zlib 1.2.2, etc.)

The bootstrap process for the standard build environment on Linux (stdenv-linux) has been improved. It is no longer dependent in its initial bootstrap stages on the system Glibc, GCC, and other tools. Rather, Nixpkgs contains a statically linked bash and curl, and uses that to download other statically linked tools. These are then used to build a Glibc and dynamically linked versions of all other tools.

This change also makes the bootstrap process faster. For instance, GCC is built only once instead of three times.

(Contributed by Armijn Hemel.)

Tarballs used by Nixpkgs are now obtained from the same server that hosts Nixpkgs (http://catamaran.labs.cs.uu.nl/). This reduces the risk of packages being unbuildable due to moved or deleted files on various servers.

There now is a generic mechanism for building Perl modules. See the various Perl modules defined in pkgs/system/all-packages-generic.nix.

Notable new packages:

Notable updates: