anchor.diff:  { lib, stdenv, fetchFromGitHub, autoreconfHook, pkg-config, gtk-doc, intltool
   , audit, glib, libusb1, libxml2
   , wrapGAppsHook
  -, gstreamer ? null
  -, gst-plugins-base ? null
  -, gst-plugins-good ? null
  -, gst-plugins-bad ? null
  -, libnotify ? null
  -, gnome ? null
  -, gtk3 ? null
  +, gstreamer
  +, gst-plugins-base
  +, gst-plugins-good
  +, gst-plugins-bad
  +, libnotify
  +, gnome
  +, gtk3
   , enableUsb ? true
   , enablePacketSocket ? true
   , enableViewer ? true
  
positive.code:       platforms = lib.platforms.unix;
      };
    }
  
  
negative.code:       (pkg: pkg != null && lib.versionAtLeast (lib.getVersion pkg) "1.0")
        [ gstreamer gst-plugins-base gst-plugins-good gst-plugins-bad ];
  in
    assert enableViewer -> enableGstPlugin;
    assert enableViewer -> gstreamerAtLeastVersion1;
  
    stdenv.mkDerivation rec {
  