anchor.diff:  , zlib, fftw, opensubdiv, freetype, jemalloc, ocl-icd, addOpenGLRunpath
   , jackaudioSupport ? false, libjack2
   , cudaSupport ? config.cudaSupport or false, cudatoolkit
  +, optixSupport ? config.optixSupport or false
   , colladaSupport ? true, opencollada
   , makeWrapper
   , pugixml, llvmPackages, SDL, Cocoa, CoreGraphics, ForceFeedback, OpenAL, OpenGL
  
positive.code: }:
  
  with lib;
  
  let python = python3Packages.python; in
  
  stdenv.mkDerivation rec {
    pname = "blender";
    version = "2.91.0";
  
  
negative.code:     # Clang doesn't support "-export-dynamic"
      ++ optional stdenv.cc.isClang "-DPYTHON_LINKFLAGS="
      ++ optional jackaudioSupport "-DWITH_JACK=ON"
      ++ optional cudaSupport "-DWITH_CYCLES_CUDA_BINARIES=ON"
      ++ optional optixSupport [
        "-DWITH_CYCLES_DEVICE_OPTIX=ON"
        "-DOPTIX_ROOT_DIR=${optix}"
      ];
  
    NIX_CFLAGS_COMPILE = "-I${ilmbase.dev}/include/OpenEXR -I${python}/include/${python.libPrefix}";
  
  