Building B2G with Nix package manager

config.nix

{
  allowUnfree = true; 
  packageOverrides = pkgs : with pkgs; rec {
    # Tested with:
    # $ nix-env -i b2g-env
    # $ b2g-env
    # $ git clone https://github.com/mozilla-b2g/B2G b2g
    # $ cd b2g
    # $ REPO_INIT_FLAGS="--depth=1" ./config.sh nexus-5
    # $ ./build.sh
    # This build will fail trying to run 'xpcshell' from the
    # binary B2G SDK that it downloads. After this failure run:
    # $ find ./gaia/b2g_sdk/ -type f -executable -exec patchelf --set-rpath /lib64 {} \;
    # Then run the build again. This only needs to be done on the
    # initial build when the SDK is downloaded. Need to find a way
    # to work around this.
    b2g = buildFHSUserEnv {
      name = "b2g-env";
      targetPkgs = pkgs: with pkgs; [ 
        stdenv pkgconfig gtk glib gobjectIntrospection dbus_libs dbus_glib alsaLib
                      xlibs.libXrender xlibs.libX11 xlibs.libXext xlibs.libXft xlibs.libXt
                      xlibs.libXdamage xlibs.libXfixes xlibs.libXcomposite
                      ats pango freetype fontconfig gdk_pixbuf cairo python
                      git autoconf213 unzip zip yasm alsaLib dbus_libs which atk
                      bison bzip2 curl flex gawk gnumake382 gnupatch mesa libxml2
                      gcc48_multi oraclejdk gnupg1 git ccache perl openssl
                      file curl wget cacert m4 patchelf 
      ];
      multiPkgs = pkgs: with pkgs; [
        ncurses zlib
      ];
      runScript = "bash";
      profile = ''
       export SHELL=/bin/bash
       export C_INCLUDE_PATH=/usr/include
       export CPLUS_INCLUDE_PATH=/usr/include
       export LIBRARY_PATH=/lib:/lib64
       export LD_LIBRARY_PATH=/lib:/lib64
       export AUTOCONF=autoconf
       export GIT_SSL_CAINFO="${cacert}/etc/ca-bundle.crt"
     '';
    };
  };
}