anchor.diff:      pango
       sqlite
       wayland
  +  ] ++ optionals (xorg != null) [
       xorg.libX11
       xorg.libXau
       xorg.libXcomposite
  
positive.code:     gnutls
      gst-plugins-base
      gstreamer
      gtk2
      gtk3
      harfbuzz
      icu
  
negative.code: 
  with {
    inherit (stdenv.lib)
      cmFlag
      optionals;
  };
  
  assert xorg != null ->
    xorg.libX11 != null;
  
  stdenv.mkDerivation rec {
    name = "webkitgtk-2.12.0";
  
    src = fetchurl {
      url = "http://webkitgtk.org/releases/${name}.tar.xz";
      sha256 = "a68604f8fd1bcb247d647709290226289b90c16acb1f3730538b688db8df5ea6";
    };
  
    nativeBuildInputs = [
      bison
  