anchor.diff:  
     src = fetchurl {
       url = "http://www.wireshark.org/download/src/all-versions/wireshark-${version}.tar.bz2";
  -    sha256 = "049r5962yrajhhz9r4dsnx403dab50d6091y2mw298ymxqszp9s2";
  +    sha256 = "1j4sc3pmy8l6k41007spglcqiabjlzc7f85pn3jmjr9ksv9qipbm";
     };
   
     nativeBuildInputs = [
  
positive.code: with stdenv.lib;
  
  let
    version = "2.2.4";
    variant = if withGtk then "gtk" else if withQt then "qt" else "cli";
  
  in stdenv.mkDerivation {
  
negative.code:     ++ optionals stdenv.isLinux  [ libcap libnl ]
      ++ optionals stdenv.isDarwin [ SystemConfiguration ApplicationServices gmp ];
  
    patches = [ ./wireshark-lookup-dumpcap-in-path.patch ];
  
    postInstall = optionalString (withQt || withGtk) ''
      ${optionalString withGtk ''
  