anchor.diff:      sha256 = "920492895db8013f6cc0179293147f830b8c7b21fdfc839b6bad760c27459d9f";
     };
   
  +  patches = [
  +    # fix RSA key loading with cryptography 3.1, remove >2.7.1
  +    (fetchpatch {
  +      url = "https://github.com/paramiko/paramiko/commit/81064206bf3cec2ca4372257ff138481e1227b91.patch";
  +      sha256 = "01b87ffgyvd6rilp1w1kf7lk29z706ch39nwl21ifklqpjhmazww";
  +    })
  +  ];
     checkInputs = [ invoke pytest mock pytest-relaxed ];
     propagatedBuildInputs = [ bcrypt cryptography pynacl pyasn1 ];
   
  
positive.code: { pkgs
  , buildPythonPackage
  , fetchPypi
  , cryptography
  , bcrypt
  , invoke
  
negative.code: 
    # 2 sftp tests fail (skip for now)
    # test_config relies on artifacts to be to downloaded
    # RSA tests don't have valid keys
    checkPhase = ''
      pytest tests \
        --ignore=tests/test_sftp.py \
  