anchor.diff:    ];
   
     postUnpack = ''
  -    # Add data files for tests, otherwise tests attempt network access.
  +    # Add data files for tests, otherwise tests attempt network access
       mkdir $sourceRoot/tests/data
       ( cd $sourceRoot/tests/data
         ln -s ${robertaVocab} roberta-base-vocab.json
  
positive.code: { lib
  , stdenv
  , fetchFromGitHub
  , fetchurl
  , buildPythonPackage
  , rustPlatform
  , setuptools-rust
  , libiconv
  , numpy
  , datasets
  , pytestCheckHook
  , requests
  }:
  
  let
    robertaVocab = fetchurl {
      url = "https://s3.amazonaws.com/models.huggingface.co/bert/roberta-base-vocab.json";
      sha256 = "0m86wpkfb2gdh9x9i9ng2fvwk1rva4p0s98xw996nrjxs7166zwy";
  
negative.code:     url = "https://s3.amazonaws.com/models.huggingface.co/bert/openai-gpt-merges.txt";
      sha256 = "09a754pm4djjglv3x5pkgwd6f79i2rq8ydg0f7c3q1wmwqdbba8f";
    };
  in
  buildPythonPackage rec {
    pname = "tokenizers";
    version = "0.12.1";
  
    disabled = pythonOlder "3.7";
  
    src = fetchFromGitHub {
      owner = "huggingface";
      repo = pname;
      rev = "python-v${version}";
      hash = "sha256-XIXKgcqa6ToAH4OkyaaJALOS9F+sD8d5Z71RttRcIsw=";
    };
  
    cargoDeps = rustPlatform.fetchCargoTarball {
      inherit src sourceRoot;
      name = "${pname}-${version}";
      sha256 = "sha256-Euvf0LNMa2Od+6gY1Ldge/7VPrH5mJoZduRRsb+lM/E=";
    };
  
    sourceRoot = "source/bindings/python";
  
    nativeBuildInputs = [
      pkg-config
      setuptools-rust
    ] ++ (with rustPlatform; [
      cargoSetupHook
      rust.cargo
      rust.rustc
    ]);
  
    buildInputs = [
      openssl
    ] ++ lib.optionals stdenv.isDarwin [
      libiconv
    ];
  
  