anchor.diff:  stdenv.mkDerivation rec {
     name = "fmod-${version}";
     version = "4.44.64";
  +  shortVersion = builtins.replaceStrings [ "." ] [ "" ] version;
   
  -  src = fetchurl {
  -    url = "https://zdoom.org/files/fmod/fmodapi44464linux.tar.gz";
  +  src = fetchurl (if stdenv.isLinux then {
  +    url = "https://zdoom.org/files/fmod/fmodapi${shortVersion}linux.tar.gz";
       sha256 = "047hk92xapwwqj281f4zwl0ih821rrliya70gfj82sdfjh9lz8i1";
  -  };
  +  } else {
  +    url = "https://zdoom.org/files/fmod/fmodapi${shortVersion}mac-installer.dmg";
  +    sha256 = "1m1y4cpcwpkl8x31d3s68xzp107f343ma09w2437i2adn5y7m8ii";
  +  });
  +
  +  nativeBuildInputs = [ undmg ];
   
     dontStrip = true;
     dontPatchELF = true;
     dontBuild = true;
   
  -  installPhase = ''
  +  installPhase = lib.optionalString stdenv.isLinux ''
       install -Dm755 api/lib/libfmodex${bits}-${version}.so $out/lib/libfmodex-${version}.so
       ln -s libfmodex-${version}.so $out/lib/libfmodex.so
       patchelf --set-rpath ${libPath} $out/lib/libfmodex.so
  +  '' + lib.optionalString stdenv.isDarwin ''
  +    install -D api/lib/libfmodex.dylib $out/lib/libfmodex.dylib
  +    install -D api/lib/libfmodexL.dylib $out/lib/libfmodexL.dylib
  +  '' + ''
       cp -r api/inc $out/include
     '';
   
  
positive.code: { stdenv, lib, fetchurl, alsaLib, libpulseaudio }:
  
  let
    bits = stdenv.lib.optionalString (stdenv.system == "x86_64-linux") "64";
  
negative.code:     description = "Programming library and toolkit for the creation and playback of interactive audio";
      homepage    = http://www.fmod.org/;
      license     = licenses.unfreeRedistributable;
      platforms   = [ "x86_64-linux" "i686-linux" "x86_64-darwin" ];
      maintainers = [ maintainers.lassulus ];
    };
  }
  