anchor.diff:  , python3
   }:
   
  -stdenv.mkDerivation rec {
  +stdenv.mkDerivation (finalAttrs: {
     pname = "x16-rom";
  -  version = "40";
  +  version = "41";
   
     src = fetchFromGitHub {
       owner = "commanderx16";
  -    repo = pname;
  -    rev = "r${version}";
  -    hash = "sha256-5oqttuTJiJOUENncOJipAar22OsI1uG3G69m+eYoSh0=";
  +    repo = "x16-rom";
  +    rev = "r${finalAttrs.version}";
  +    hash = "sha256-kowdyUVi3hliqkL8VQo5dS3Dpxd4LQi5+5brkdnv0lE=";
     };
   
     nativeBuildInputs = [
  
positive.code:   installPhase = ''
      runHook preInstall
  
      install -Dm 444 -t $out/share/${pname} build/x16/rom.bin
      install -Dm 444 -t $out/share/doc/${pname} README.md
  
      runHook postInstall
    '';
  
negative.code:   };
  
    passthru = {
      # upstream project recommends emulator and rom to be synchronized;
      # passing through the version is useful to ensure this
      inherit (finalAttrs) version;
    };
  })
  