anchor.diff:  
     postPatch = ''
       substituteInPlace setup.py \
  -      --replace "bidict>=0.17,<0.18" "bidict" \
  -      --replace "more-itertools>=4.0,<8.0" "more-itertools" \
  -      --replace "pendulum>=2.0,<=3.0,!=2.0.5,!=2.1.0" "pendulum>=2.0,<=3.0"
  +      --replace "'attrs>=18.2,<19.4'" "'attrs'"
     '';
   
     propagatedBuildInputs = [
  
positive.code: { lib, buildPythonPackage, fetchPypi, pythonOlder
  , attrs
  , bidict
  , bitstruct
  
negative.code:   # No tests
    doCheck = false;
  
    meta = with lib; {
      homepage = "https://github.com/thebigmunch/audio-metadata";
      description = "A library for reading and, in the future, writing metadata from audio files";
  