anchor.diff:      ++ lib.optionals enableEXR [ openexr ilmbase ]
       ++ lib.optional enableJPEG2K jasper
       ++ lib.optional enableFfmpeg ffmpeg
  -    ++ lib.optionals enableGStreamer (with gst_all; [ gstreamer gst-plugins-base ])
  +    ++ lib.optionals enableGStreamer (with gst_all_1; [ gstreamer gst-plugins-base ])
       ++ lib.optional enableEigen eigen
       ++ lib.optionals stdenv.isDarwin (with darwin.apple_sdk.frameworks; [ Cocoa QTKit ])
       ;
  
positive.code: , enableEXR ? (!stdenv.isDarwin), openexr, ilmbase
  , enableJPEG2K ? true, jasper
  , enableFfmpeg ? false, ffmpeg
  , enableGStreamer ? false, gst_all
  , enableEigen ? true, eigen
  , darwin
  }:
  
negative.code:     (opencvFlag "JPEG" enableJPEG)
      (opencvFlag "PNG" enablePNG)
      (opencvFlag "OPENEXR" enableEXR)
      (opencvFlag "GSTREAMER" enableGStreamer)
    ];
  
    enableParallelBuilding = true;
  