anchor.diff:      wtFlag;
   };
   
  +assert qt5 != null -> qt5.qtbase != null;
  +
   stdenv.mkDerivation rec {
     name = "mkvtoolnix-${version}";
  -  version = "8.8.0";
  +  version = "8.9.0";
   
     src = fetchurl {
       url = "http://www.bunkus.org/videotools/mkvtoolnix/sources/${name}.tar.xz";
  -    sha256 = "1751sf6brwwl1dq64155s4a12784q35dyqfy028qrwr1ilafhbci";
  +    sha256 = "1m50m8lkfpk0663zhhx9alvprf2y6b4lj9wj29xn3a1rjf2b421j";
     };
   
     nativeBuildInputs = [
  
positive.code: , libmatroska
  , libogg
  , libvorbis
  , qt5
  , xdg-utils
  , zlib
  # pugixml (not packaged)
  }:
  
  with {
  
negative.code:     libmatroska
      libogg
      libvorbis
      pugixml
      xdg-utils
      zlib
    ] ++ optionals (qt5 != null) [
      qt5.qtbase
    ];
  
    postPatch = ''
      patchShebangs ./rake.d/
      patchShebangs ./Rakefile
    '';
  
    configureFlags = [
  