anchor.diff: -{stdenv, lib, fetchurl, makeDesktopItem, copyDesktopItems, cmake, pkg-config, zlib, bzip2, libjpeg, SDL, SDL_mixer, gtk2}:
  +{ stdenv, lib, fetchurl, makeDesktopItem, copyDesktopItems, cmake, pkg-config, zlib, bzip2, libjpeg, SDL, SDL_mixer, gtk2 }:
   
  -let
  -  desktopItem = makeDesktopItem {
  -    name = "ecwolf";
  -    exec = "ecwolf";
  -    comment = "Enhanced Wolfenstein 3D port";
  -    desktopName = "Wolfenstein 3D";
  -    categories = "Game;";
  -  };
  -in
   stdenv.mkDerivation rec {
     pname = "ecwolf";
     version = "1.3.3";
  
positive.code:     sha256 = "1sbdv672dz47la5a5qwmdi1v258k9kc5dkx7cdj2b6gk8nbm2srl";
    };
  
    nativeBuildInputs = [ cmake pkg-config ];
    buildInputs = [ zlib bzip2 libjpeg SDL SDL_mixer gtk2 copyDesktopItems ];
  
    desktopItems = [ desktopItem ];
  
    # Change the location where the ecwolf executable looks for the ecwolf.pk3
    # file.
  
negative.code:     sed -i -e "s|ecwolf.pk3|$out/share/ecwolf/ecwolf.pk3|" src/version.h
    ''
    # Disable app bundle creation on Darwin. It fails, and it is not needed to run it from the Nix store
    + lib.optionalString stdenv.isDarwin ''
      sed -i -e "s|include(\''${CMAKE_CURRENT_SOURCE_DIR}/macosx/install.txt)||" src/CMakeLists.txt
    '';
  
  