anchor.diff:    meta = with stdenv.lib; {
       homepage = "https://github.com/huggingface/transformers";
       description = "State-of-the-art Natural Language Processing for TensorFlow 2.0 and PyTorch";
  +    changelog = "https://github.com/huggingface/transformers/releases/tag/v${version}";
       license = licenses.asl20;
       platforms = platforms.unix;
       maintainers = with maintainers; [ danieldk pashashocky ];
  
positive.code: 
    postPatch = ''
      substituteInPlace setup.py \
        --replace "tokenizers == 0.8.1.rc1" "tokenizers>=0.8"
    '';
  
    preCheck = ''
      export HOME="$TMPDIR"
      cd tests
    '';
  
    # Disable tests that require network access.
    disabledTests = [
      "test_all_tokenizers"
      "test_batch_encoding_is_fast"
      "test_batch_encoding_pickle"
  
negative.code:     "test_hf_api"
      "test_outputs_can_be_shorter"
      "test_outputs_not_longer_than_maxlen"
      "test_padding_accepts_tensors"
      "test_pretokenized_tokenizers"
      "test_tokenizer_equivalence_en_de"
      "test_tokenizer_from_model_type"
  