anchor.diff:  
       enableParallelBuilding = true;
         
  +    # Hack to work around make's idea of -lbz2 dependency
  +    preConfigure =
  +      ''
  +        find . -name Makefile.in -execdir sed -i '{}' -e '1ivpath %.so ${
  +          stdenv.lib.concatStringsSep ":" 
  +            (map (s : s + "/lib") (buildInputs ++ [stdenv.gcc.libc]))
  +        }' ';'
  +      '';
  +
       # !!! Temporary hack.
  -    preBuild = ''
  -      export NIX_ENFORCE_PURITY=
  -    '';
  -
  -    # Hack to work around make's idea of -lbz2 dependency
  -    preConfigure = ''
  -     find . -name Makefile.in -execdir sed -i '{}' -e '1ivpath %.so ${
  -       stdenv.lib.concatStringsSep ":" 
  -         (map (s : s + "/lib") (buildInputs ++ [stdenv.gcc.libc]))
  -     }' ';'
  -    '';
  +    preBuild =
  +      ''
  +        export NIX_ENFORCE_PURITY=
  +      '';
   
       installFlags = "SKIP_GRE_REGISTRATION=1";
   
  
positive.code: { stdenv, fetchurl, pkgconfig, gtk, pango, perl, python, zip, libIDL
  , libjpeg, libpng, zlib, cairo, dbus, dbus_glib, bzip2, xlibs
  , freetype, fontconfig, file, alsaLib, nspr, nss, libnotify
  , libvpx, yasm, mesa, wirelesstools
  
  , # If you want the resulting program to call itself "Firefox" instead
    # of "Shiretoko" or whatever, enable this option.  However, those
  
negative.code:     buildInputs =
        [ pkgconfig gtk perl zip libIDL libjpeg zlib cairo bzip2 python
          dbus dbus_glib pango freetype fontconfig alsaLib nspr libnotify
          xlibs.pixman libvpx yasm mesa
        ];
  
      propagatedBuildInputs = [xulrunner];
  