anchor.diff:  
         ${installExtraFiles vgg}
         ${installExtraFiles boostdesc}
  +      ${installExtraFiles face}
   
         mkdir -p "${tinyDnn.dst}"
         ln -s "${tinyDnn.src}" "${tinyDnn.dst}/${tinyDnn.md5}-${tinyDnn.name}"
       '');
   
     buildInputs =
  -       [ zlib pcre hdf5 ]
  +       [ zlib pcre hdf5 glog boost google-gflags protobuf ]
  +    ++ lib.optional (!stdenv.isDarwin) caffe
       ++ lib.optional enablePython pythonPackages.python
       ++ lib.optional enableGtk2 gtk2
       ++ lib.optional enableGtk3 gtk3
  +    ++ lib.optional enableVtk vtk
       ++ lib.optional enableJPEG libjpeg
       ++ lib.optional enablePNG libpng
       ++ lib.optional enableTIFF libtiff
  
positive.code:     ++ lib.optionals (enableFfmpeg && stdenv.isDarwin)
                       [ VideoDecodeAcceleration bzip2 ]
      ++ lib.optionals enableGStreamer (with gst_all_1; [ gstreamer gst-plugins-base ])
      ++ lib.optional enableEigen eigen
      ++ lib.optional enableOpenblas openblas
      # There is seemingly no compile-time flag for Tesseract.  It's
  
negative.code:     # tesseract & leptonica.
      ++ lib.optionals enableTesseract [ tesseract leptonica ]
      ++ lib.optional enableCuda cudatoolkit
      ++ lib.optionals stdenv.isDarwin [ AVFoundation Cocoa QTKit ]
      ++ lib.optionals enableDocs [ doxygen graphviz-nox ];
  
  