anchor.diff:  , gst-plugins-base
   , gstreamer
   , libdrm
  -, mesa_noglu
  +, libx11
  +, libxcomposite
  +, libxdamage
  +, libxext
  +, libxfixes
  +, libxrandr
  +, opengl-dummy
   , pango
   , wayland
  -, xorg
   
   , channel
   }:
  
positive.code:     "--disable-standalone"
      "--disable-debug"
      "--${boolEn doCheck}-unit-tests"
      "--${boolEn (cairo != null)}-cairo"
      "--disable-profile"
      "--disable-maintainer-flags"
      "--enable-deprecated"
      "--${boolEn (glib != null)}-glibtest"
      "--${boolEn (glib != null)}-glib"
      "--${boolEn (pango != null)}-cogl-pango"
      "--${boolEn (
        gstreamer != null
        && gst-plugins-base != null)}-cogl-gst"
      "--enable-cogl-path"
      "--${boolEn (gdk-pixbuf != null)}-gdk-pixbuf"
      "--disable-quartz-image"
      "--disable-examples-install"
      "--enable-gles1"
      "--enable-gles2"
      "--enable-gl"
      "--enable-cogl-gles2"
      "--enable-glx"
      "--disable-wgl"
      "--enable-null-egl-platform"
      "--disable-gdl-egl-platform"
      "--enable-wayland-egl-platform"
      "--enable-kms-egl-platform"
      "--enable-wayland-egl-server"
      "--disable-android-egl-platform"
      "--disable-mir-egl-platform"
      "--enable-xlib-egl-platform"
      "--disable-gtk-doc"
      "--disable-gtk-doc-html"
      "--disable-gtk-doc-pdf"
      "--enable-nls"
      "--enable-rpath"
      "--${boolEn (gobject-introspection != null)}-introspection"
      "--with-x"
    ];
  
    doCheck = false;
  
negative.code:     gobject-introspection
      gst-plugins-base
      gstreamer
      opengl-dummy
      pango
    ] ++ optionals opengl-dummy.egl [
      libdrm
      wayland
    ] ++ optionals (opengl-dummy.glx || opengl-dummy.egl) [
      libx11
      libxcomposite
      libxdamage
      libxext
      libxfixes
      libxrandr
    ];
  
    postPatch =
  