anchor.diff:      pyyaml
     ] ++ lib.optional (pythonOlder "3.5") typing;
   
  +  checkInputs = [ hypothesis ];
     checkPhase = ''
  -    ${cudaStubEnv}python test/run_test.py --exclude dataloader sparse torch utils distributed
  +    ${cudaStubEnv}python test/run_test.py --exclude dataloader sparse torch utils thd_distributed distributed cpp_extensions
     '';
   
     meta = {
  
positive.code: { buildPythonPackage, pythonOlder,
    cudaSupport ? false, cudatoolkit ? null, cudnn ? null,
    fetchFromGitHub, lib, numpy, pyyaml, cffi, typing, cmake,
    linkFarm, symlinkJoin,
    utillinux, which }:
  
  
negative.code:     repo   = "pytorch";
      rev    = "v${version}";
      fetchSubmodules = true;
      sha256 = "076cpbig4sywn9vv674c0xdg832sdrd5pk1d0725pjkm436kpvlm";
    };
  
    preConfigure = lib.optionalString cudaSupport ''
  