anchor.diff:      configurePhase = "rm configure";
       buildPhase = "make -f Makefile.libretro";
     };
  -  
  +
     picodrive = (mkLibRetroCore rec {
       core = "picodrive";
       src = fetchRetro {
  
positive.code:     makefile = "Makefile";
      buildPhase = "make";
    };
   
    parallel-n64 = (mkLibRetroCore rec {
      core = "parallel-n64";
      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 {
  