anchor.diff:  { stdenv, fetchFromGitHub, pkgconfig, autoconf, automake
  -, drake, ruby, file, xdg_utils, gettext, expat, qt5, boost
  -, libebml, zlib, libmatroska, libogg, libvorbis, flac
  +, drake, ruby, docbook_xsl, file, xdg_utils, gettext, expat, qt5, boost
  +, libebml, zlib, libmatroska, libogg, libvorbis, flac, libxslt
   , withGUI ? true
   }:
   
  
positive.code: 
  stdenv.mkDerivation rec {
    name = "mkvtoolnix-${version}";
    version = "9.8.0";
  
    src = fetchFromGitHub {
      owner = "mbunkus";
      repo = "mkvtoolnix";
      rev = "release-${version}";
      sha256 = "1hnk92ksgg290q4kwdl8jqrz7vzlwki4f85bb6kgdgzpjkblw76n";
    };
  
    nativeBuildInputs = [ pkgconfig autoconf automake gettext drake ruby ];
  
    buildInputs = [
      expat file xdg_utils boost libebml zlib libmatroska libogg
  
negative.code:     "--disable-precompiled-headers"
      "--disable-static-qt"
      "--with-gettext"
      "--with-docbook-xsl-root=${docbook_xsl}/share/xml/docbook-xsl"
      (enableFeature withGUI "qt")
    ];
  
  