anchor.diff:  
   buildPythonPackage rec {
     pname   = "pytorch-metric-learning";
  -  version = "0.9.81";
  +  version = "0.9.94";
   
     disabled = isPy27;
   
     src = fetchFromGitHub {
       owner = "KevinMusgrave";
       repo = pname;
  -    rev = "cb23328aba64f7f4658374cc2920ef5d56cda5c8";  # no version tag
  -    sha256 = "0c2dyi4qi7clln43481xq66f6r4fadrz84jphjc5phz97bp33ds8";
  +    rev = "v${version}";
  +    sha256 = "1i2m651isa6xk3zj8dhzdbmd1bdzl51bh6rxifx6gg22hfa5dj9a";
     };
   
     propagatedBuildInputs = [
  
positive.code: , isPy27
  , numpy
  , scikitlearn
  , pytorch
  , torchvision
  , tqdm
  
negative.code:     tqdm
    ];
  
    preCheck = ''
      export HOME=$TMP
      export TEST_DEVICE=cpu
      export TEST_DTYPES=float32,float64  # half-precision tests fail on CPU
    '';
    # package only requires `unittest`, but use `pytest` to exclude tests
    checkInputs = [ pytestCheckHook ];
    disabledTests = [
      # requires FAISS (not in Nixpkgs)
      "test_accuracy_calculator_and_faiss"
      # require network access:
      "test_get_nearest_neighbors"
      "test_tuplestoweights_sampler"
      "test_untrained_indexer"
    ];
  
    meta = {
      description = "Metric learning library for PyTorch";
      homepage = "https://github.com/KevinMusgrave/pytorch-metric-learning";
  