anchor.diff:      ++ optional cudaSupport cudatoolkit
       ++ optional colladaSupport opencollada
       ++ optional spaceNavSupport libspnav;
  -  pythonPath = with python3Packages; [ numpy requests ];
  +  pythonPath = with python39Packages; [ numpy requests ];
   
     postPatch = ''
       # allow usage of dynamically linked embree
  
positive.code: { config, stdenv, lib, fetchurl, fetchzip, boost, cmake, ffmpeg, gettext, glew
  , ilmbase, libXi, libX11, libXext, libXrender
  , libjpeg, libpng, libsamplerate, libsndfile
  , libtiff, libGLU, libGL, openal, opencolorio, openexr, openimagedenoise, openimageio2, openjpeg, python3Packages
  , openvdb, libXxf86vm, tbb, alembic
  , zlib, fftw, opensubdiv, freetype, jemalloc, ocl-icd, addOpenGLRunpath
  , jackaudioSupport ? false, libjack2
  
negative.code:       "-DPYTHON_VERSION=${python.pythonVersion}"
        "-DWITH_PYTHON_INSTALL=OFF"
        "-DWITH_PYTHON_INSTALL_NUMPY=OFF"
        "-DPYTHON_NUMPY_PATH=${python39Packages.numpy}/${python.sitePackages}"
        "-DPYTHON_NUMPY_INCLUDE_DIRS=${python39Packages.numpy}/${python.sitePackages}/numpy/core/include"
        "-DWITH_PYTHON_INSTALL_REQUESTS=OFF"
        "-DWITH_OPENVDB=ON"
        "-DWITH_TBB=ON"
  