anchor.diff:      libogg
       libvorbis
       pugixml
  +    qt5
       xdg-utils
       zlib
  -  ] ++ optionals (qt5 != null) [
  -    qt5.qtbase
     ];
   
     postPatch = ''
  
positive.code:     ./drake install -j $NIX_BUILD_CORES
    '';
  
    meta = with stdenv.lib; {
      description = "Cross-platform tools for Matroska";
      homepage = http://www.bunkus.org/videotools/mkvtoolnix/;
  
negative.code:     wtFlag;
  in
  
  stdenv.mkDerivation rec {
    name = "mkvtoolnix-${version}";
    version = "9.3.1";
  
    src = fetchurl {
      url = "https://mkvtoolnix.download/sources/${name}.tar.xz";
      sha256 = "f3695761bf0a5fdcd6144cfb0a624094c10c9d66d43a340ebb917b7c6a8b39a2";
    };
  
    nativeBuildInputs = [
  