anchor.diff:       git
        numpy.blas
     ];
  -  
  +
     propagatedBuildInputs = [
       cffi
       numpy
  
positive.code:     owner  = "pytorch";
      repo   = "pytorch";
      rev    = "v${version}";
      sha256 = "112mp3r70d8f15dhxm6k7912b5i6c2q8hv9462s808y84grr2jdm";
    };
  
    checkPhase = ''
  
negative.code:   preConfigure = ''
      export NO_CUDA=1
    '';
  
    meta = {
      description = "Tensors and Dynamic neural networks in Python with strong GPU acceleration.";
      homepage = http://pytorch.org/;
  