anchor.diff:  
       NIX_CFLAGS_LINK = "-lopenal -lfluidsynth";
   
  +    desktopItems = [
  +      (makeDesktopItem {
  +        name = "gzdoom";
  +        exec = "gzdoom";
  +        desktopName = "GZDoom";
  +        categories = "Game;";
  +      })
  +    ];
  +
       installPhase = ''
  +      runHook preInstall
  +
         install -Dm755 gzdoom "$out/lib/gzdoom/gzdoom"
         for i in *.pk3; do
           install -Dm644 "$i" "$out/lib/gzdoom/$i"
  
positive.code:       done
        mkdir $out/bin
        makeWrapper $out/lib/gzdoom/gzdoom $out/bin/gzdoom
      '';
  
      meta = with lib; {
  
negative.code: { lib, stdenv, fetchFromGitHub, cmake, makeWrapper, openal, fluidsynth_1
  , soundfont-fluid, libGL, SDL2, bzip2, zlib, libjpeg, libsndfile, mpg123
  , game-music-emu, pkg-config, copyDesktopItems, makeDesktopItem }:
  
  let
    zmusic-src = fetchFromGitHub {
  