anchor.diff:  
   buildPythonPackage rec {
     pname = "canmatrix";
  -  version = "0.8";
  +  version = "0.9.1";
   
     # uses fetchFromGitHub as PyPi release misses test/ dir
     src = fetchFromGitHub {
       owner = "ebroecker";
       repo = pname;
       rev = version;
  -    sha256 = "1wzflapyj2j4xsi7d7gfmznmxbgr658n092xyq9nac46rbhpcphg";
  +    sha256 = "129lcchq45h8wqjvvn0rwpbmih4m0igass2cx7a21z94li97hcia";
     };
   
     propagatedBuildInputs = [
       # required
       attrs
       bitstruct
  +    click
       future
       pathlib2
       # optional
  
positive.code: , pythonOlder
  , attrs
  , bitstruct
  , future
  , pathlib2
  , typing
  
negative.code:     pyyaml
    ] ++ lib.optional (pythonOlder "3.5") typing;
  
    postPatch = ''
      substituteInPlace setup.py \
        --replace "version = versioneer.get_version()" "version = \"${version}\""
    '';
  
    checkInputs = [
      pytest
    ];
  
    # long_envvar_name_imports requires stable key value pair ordering
    checkPhase = ''
      pytest -s src/canmatrix -k 'not long_envvar_name_imports'
    '';
  
    meta = with lib; {
  