anchor.diff:        [ pkgconfig gtk perl zip libIDL libjpeg libpng zlib cairo bzip2
           python dbus dbus_glib pango freetype fontconfig xlibs.libXi
           xlibs.libX11 xlibs.libXrender xlibs.libXft xlibs.libXt file
  -        alsaLib nspr /* nss */ libnotify xlibs.pixman libvpx yasm mesa
  +        alsaLib nspr /* nss */ libnotify xlibs.pixman yasm mesa
   	xlibs.libXScrnSaver xlibs.scrnsaverproto
   	xlibs.libXext xlibs.xextproto
         ];
  
positive.code: 
  rec {
  
    firefoxVersion = "4.0";
    
    xulVersion = "2.0"; # 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 = "403da9dd65662e5c4dd34299214e04cb6f80575e";
    };
  
    
  
negative.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
  , yasm, mesa
  
  , # If you want the resulting program to call itself "Firefox" instead
    # of "Shiretoko" or whatever, enable this option.  However, those
  