anchor.diff:    sourceName = "higan_v${version}-source";
   
     src = fetchurl {
  -    urls = [ "http://byuu.org/files/${sourceName}.tar.xz" "http://byuu.net/files/${sourceName}.tar.xz" ];
  +    urls = [ "http://files.byuu.org/download/${sourceName}.tar.xz" ];
       sha256 = "06qm271pzf3qf2labfw2lx6k0xcd89jndmn0jzmnc40cspwrs52y";
       curlOpts = "--user-agent 'Mozilla/5.0'"; # the good old user-agent trick...
     };
   
  -  buildInputs = with stdenv.lib;
  +  buildInputs =
     [ pkgconfig libX11 libXv udev mesa SDL libao openal pulseaudio ]
     ++ optionals (guiToolkit == "gtk") [ gtk ]
     ++ optionals (guiToolkit == "qt4") [ qt4 ];
  
positive.code: assert guiToolkit == "gtk" || guiToolkit == "qt4";
  assert (guiToolkit == "gtk" -> gtk != null) || (guiToolkit == "qt4" -> qt4 != null);
  
  stdenv.mkDerivation rec {
  
    name = "higan-${version}";
  
negative.code:     chmod +x $out/bin/higan-init.sh
    '';
  
    meta = {
      description = "An open-source, cycle-accurate Nintendo multi-system emulator";
      longDescription = ''
        Higan (formerly bsnes) is a Nintendo multi-system emulator.
  