anchor.diff:      name = "beetle-saturn-${der.version}";
       meta.platforms = [ "x86_64-linux" "aarch64-linux" ];
     };
  -  
  +
     beetle-supergrafx = (mkLibRetroCore rec {
       core = "mednafen-supergrafx";
       src = fetchRetro {
  
positive.code:     configurePhase = "rm configure";
      buildPhase = "make -f Makefile.libretro";
    };
    
    picodrive = (mkLibRetroCore rec {
      core = "picodrive";
      src = fetchRetro {
  
negative.code:     buildPhase = "make";
      name = "beetle-pce-fast-${der.version}";
    };
  
    beetle-pcfx = (mkLibRetroCore rec {
      core = "mednafen-pcfx";
      src = fetchRetro {
  