anchor.diff:      makefile = "Makefile";
       buildPhase = "make";
     };
  - 
  +
     parallel-n64 = (mkLibRetroCore rec {
       core = "parallel-n64";
       src = fetchRetro {
  
positive.code:     buildPhase = "make";
      name = "beetle-pce-fast-${der.version}";
    };
    
    beetle-pcfx = (mkLibRetroCore rec {
      core = "mednafen-pcfx";
      src = fetchRetro {
  
negative.code:     name = "beetle-saturn-${der.version}";
      meta.platforms = [ "x86_64-linux" "aarch64-linux" ];
    };
  
    beetle-supergrafx = (mkLibRetroCore rec {
      core = "mednafen-supergrafx";
      src = fetchRetro {
  