anchor.diff:  
   with {
     inherit (stdenv.lib)
  -    cmFlag;
  +    cmFlag
  +    optionals;
   };
   
  +assert xorg != null ->
  +  xorg.libX11 != null;
  +
   stdenv.mkDerivation rec {
  -  name = "webkitgtk-2.10.8";
  +  name = "webkitgtk-2.12.0";
   
     src = fetchurl {
       url = "http://webkitgtk.org/releases/${name}.tar.xz";
  -    sha256 = "1a98z7fa8vxk7y2hlbnkl767908anyyxbwkyiar5gi037yr84dii";
  +    sha256 = "a68604f8fd1bcb247d647709290226289b90c16acb1f3730538b688db8df5ea6";
     };
  -
  -  patches = [
  -    (fetchTritonPatch {
  -      rev = "d3fc5e59bd2b4b465c2652aae5e7428b24eb5669";
  -      file = "webkitgtk/webkit-gtk-2.10.x-finding-harfbuzz-icu.patch";
  -      sha256 = "8eb3f4844b06c3c060233396045248a883177e9a09c491ddfaf9897d8e8ca2c4";
  -    })
  -    (fetchTritonPatch {
  -      rev = "0f1cfb237c758ea9c79fe44d6f5b5b20bcf8900f";
  -      file = "webkitgtk/webkit-gtk-2.10.7-fix-compatibility-with-glibc-2.23.patch";
  -      sha256 = "b66396c7aeddaf90360d4c37301099734925197fa664bfd7d8c6b4532624b432";
  -    })
  -  ];
  -
  -  postPatch = ''
  -    patchShebangs ./Tools
  -  '';
  -
  -  cmakeFlags = [
  -    (cmFlag "CMAKE_BUILD_TYPE" "Release")
  -    (cmFlag "PORT" "GTK")
  -    (cmFlag "ENABLE_PLUGIN_PROCESS_GTK2" (gtk2 != null))
  -
  -    (cmFlag "ENABLE_WEBKIT" true)
  -    (cmFlag "ENABLE_WEBKIT2" true)
  -    (cmFlag "ENABLE_TOOLS" true)
  -    # Shared library causes linker failure
  -    (cmFlag "SHARED_CORE" false)
  -    (cmFlag "ENABLE_API_TESTS" false)
  -
  -    (cmFlag "ENABLE_GRAPHICS_CONTEXT_3D" true)
  -    (cmFlag "ENABLE_GTKDOC" false)
  -    (cmFlag "ENABLE_INTROSPECTION" (gobject-introspection != null))
  -    (cmFlag "USE_REDIRECTED_XCOMPOSITE_WINDOW" true)
  -
  -    (cmFlag "ENABLE_DEVELOPER_MODE" false)
  -
  -    # Optional libraries
  -    (cmFlag "ENABLE_CREDENTIAL_STORAGE" (libsecret != null))
  -    (cmFlag "ENABLE_JIT" true)
  -    (cmFlag "ENABLE_FTL_JIT" false) # llvm
  -    # TODO: add gudev support
  -    (cmFlag "ENABLE_GAMEPAD_DEPRECATED" false)
  -    (cmFlag "ENABLE_GEOLOCATION" (geoclue2 != null))
  -    # TODO: add openwebrtc support
  -    (cmFlag "ENABLE_MEDIA_STREAM" false)
  -    (cmFlag "ENABLE_OPENGL" (mesa_noglu != null))
  -    (cmFlag "ENABLE_GLES2" (mesa_noglu != null))
  -    (cmFlag "ENABLE_PLUGIN_PROCESS_GTK2" (gtk2 != null))
  -    (cmFlag "ENABLE_SECCOMP_FILTERS" false)
  -    (cmFlag "ENABLE_SPELLCHECK" (enchant != null))
  -    (cmFlag "ENABLE_SUBTLE_CRYPTO" (gnutls != null))
  -    (cmFlag "ENABLE_VIDEO" (gstreamer != null && gst-plugins-base != null))
  -    (cmFlag "ENABLE_WEB_AUDIO" (gstreamer != null && gst-plugins-base != null))
  -    # TODO: add gstreamer mpeg-ts support
  -    (cmFlag "USE_GSTREAMER_MPEGTS" false)
  -    # TODO: add gstreamer GL support
  -    (cmFlag "USE_GSTREAMER_GL" false)
  -    (cmFlag "ENABLE_X11_TARGET" (xorg.libX11 != null))
  -    # TODO: add wayland support (linker errors)
  -    (cmFlag "ENABLE_WAYLAND_TARGET" (wayland != null))
  -    (cmFlag "USE_LIBNOTIFY" (libnotify != null))
  -    # TODO: add libhyphen support
  -    (cmFlag "USE_LIBHYPHEN" false)
  -
  -    #ENABLE_PLUGIN_PROCESS
  -    #ENABLE_NETWORK_PROCESS
  -    #ENABLE_DATABASE_PROCESS
  -    #ENABLE_ICONDATABASE
  -    #ENABLE_THREADED_COMPOSITOR
  -    #ENABLE_BATTERY_STATUS
  -    #ENABLE_ACCESSIBILITY
  -    #ENABLE_ALLINONE_BUILD
  -    #ENABLE_ENCRYPTED_MEDIA
  -    #ENABLE_WEBGL
  -    #ENABLE_VIDEO_TRACK
  -    #ENABLE_QUOTA
  -    #USE_EGL
  -    #ENABLE_WEB_REPLAY
  -    #ENABLE_USER_MESSAGE_HANDLERS
  -    #WebCore_USER_AGENT_SCRIPTS
  -    #ENABLE_SVG_FONTS
  -    #ENABLE_GEOLOCATION
  -    #USE_GEOCLUE2
  -    #USE_TEXTURE_MAPPER
  -    #USE_OPENGL_ES_2
  -    #USE_OPENGL
  -    #ENABLE_SMOOTH_SCROLLING
  -    #ENABLE_INDEXED_DATABASE
  -    #USE_LD_GOLD
  -    #ENABLE_ECORE_X
  -    #ENABLE_ACCESSIBILITY
  -    #ENABLE_NETSCAPE_PLUGIN_API
  -    #ENABLE_EGL
  -    #ENABLE_SPEECH_SYNTHESIS
  -  ];
  -
  -  # WebKit2 missing include path for gst-plugins-base.
  -  # https://bugs.webkit.org/show_bug.cgi?id=148894
  -  NIX_CFLAGS_COMPILE = [
  -    "-I${gst-plugins-base}/include/gstreamer-1.0"
  -  ];
   
     nativeBuildInputs = [
       bison
  
positive.code: , gnutls
  , gst-plugins-base
  , gstreamer
  , gtk2
  , gtk3
  , harfbuzz
  , icu
  
negative.code:     gnutls
      gst-plugins-base
      gstreamer
      gtk3
      harfbuzz
      icu
  