anchor.diff: -{ stdenv, lib, fetchurl, makeDesktopItem, SDL, SDL_net, SDL_sound, libGLU_combined, libpng }:
  +{ stdenv, lib, fetchurl, makeDesktopItem, SDL, SDL_net, SDL_sound, libGLU_combined, libpng, graphicsmagick }:
   
   stdenv.mkDerivation rec {
     name = "dosbox-0.74-2";
  
positive.code:   postInstall = ''
       mkdir -p $out/share/applications
       cp ${desktopItem}/share/applications/* $out/share/applications
    '';
  
    enableParallelBuilding = true;
  
negative.code: 
    buildInputs = [ SDL SDL_net SDL_sound libGLU_combined libpng ];
  
    nativeBuildInputs = [ graphicsmagick ];
  
    configureFlags = lib.optional stdenv.isDarwin "--disable-sdltest";
  
    desktopItem = makeDesktopItem {
      name = "dosbox";
      exec = "dosbox";
      icon = "dosbox";
      comment = "x86 emulator with internal DOS";
      desktopName = "DOSBox";
      genericName = "DOS emulator";
  