anchor.diff:  , ilmbase, libXi, libX11, libXext, libXrender
   , libjpeg, libpng, libsamplerate, libsndfile
   , libtiff, libGLU, libGL, openal, opencolorio, openexr, openimageio2, openjpeg, python3Packages
  -, openvdb, libXxf86vm, tbb
  +, openvdb, libXxf86vm, tbb, alembic
   , zlib, fftw, opensubdiv, freetype, jemalloc, ocl-icd, addOpenGLRunpath
   , jackaudioSupport ? false, libjack2
   , cudaSupport ? config.cudaSupport or false, cudatoolkit
  
positive.code: 
    cmakeFlags =
      [
        "-DWITH_ALEMBIC=OFF"
        "-DWITH_MOD_OCEANSIM=ON"
        "-DWITH_CODEC_FFMPEG=ON"
        "-DWITH_CODEC_SNDFILE=ON"
  
negative.code:     [ boost ffmpeg gettext glew ilmbase
        freetype libjpeg libpng libsamplerate libsndfile libtiff
        opencolorio openexr openimageio2 openjpeg python zlib fftw jemalloc
        alembic
        (opensubdiv.override { inherit cudaSupport; })
        tbb
        makeWrapper
  