anchor.diff:  
   rec {
   
  -  firefoxVersion = "15.0";
  -  
  -  xulVersion = "15.0"; # this attribute is used by other packages
  +  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";
  -    sha256 = "12f7dgcksb9d79hj0a8lxn3s81id6l2gd1pb7ls4d60kmgbg05jl";
  +    sha1 = "bdbc4b6656c59b926e18f99b3335484427d08641";
     };
  -  
  +
     commonConfigureFlags =
       [ "--enable-optimize"
         "--disable-debug"
  
positive.code:     preConfigure =
        ''
          find . -name Makefile.in -execdir sed -i '{}' -e '1ivpath %.so ${
            stdenv.lib.concatStringsSep ":" 
              (map (s : s + "/lib") (buildInputs ++ [stdenv.gcc.libc]))
          }' ';'
        '';
  
negative.code:       ] ++ commonConfigureFlags;
  
      enableParallelBuilding = true;
  
      preConfigure =
        ''
          export NIX_LDFLAGS="$NIX_LDFLAGS -L$out/lib/xulrunner-${xulVersion}"
  