anchor.diff:      wtFlag;
   in
   
  -assert qt5 != null -> qt5.qtbase != null;
  -
   stdenv.mkDerivation rec {
     name = "mkvtoolnix-${version}";
  -  version = "9.0.1";
  +  version = "9.3.1";
   
     src = fetchurl {
       url = "https://mkvtoolnix.download/sources/${name}.tar.xz";
  -    sha256 = "292504633d714c42f73f08474137e462827f6d8d570292005bbaebb8fee8e52e";
  +    sha256 = "f3695761bf0a5fdcd6144cfb0a624094c10c9d66d43a340ebb917b7c6a8b39a2";
     };
   
     nativeBuildInputs = [
  
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:     libogg
      libvorbis
      pugixml
      qt5
      xdg-utils
      zlib
    ];
  
    postPatch = ''
  