anchor.diff:      inherit src;
   
       enableParallelBuilding = true;
  -      
  +
       buildInputs =
         [ pkgconfig gtk perl zip libIDL libjpeg zlib cairo bzip2 python
           dbus dbus_glib pango freetype fontconfig alsaLib nspr nss libnotify
  
positive.code:       ] ++ commonConfigureFlags;
  
      enableParallelBuilding = true;
        
      preConfigure =
        ''
          export NIX_LDFLAGS="$NIX_LDFLAGS -L$out/lib/xulrunner-${xulVersion}"
  
negative.code: 
  rec {
  
    firefoxVersion = "15.0.1";
  
    xulVersion = "15.0.1"; # this attribute is used by other packages
  
  
    src = fetchurl {
      url = "http://releases.mozilla.org/pub/mozilla.org/firefox/releases/${firefoxVersion}/source/firefox-${firefoxVersion}.source.tar.bz2";
      sha1 = "bdbc4b6656c59b926e18f99b3335484427d08641";
    };
  
    commonConfigureFlags =
      [ "--enable-optimize"
        "--disable-debug"
  