anchor.diff:    src = fetchFromGitHub {
       owner = "Azure";
       repo = "msrest-for-python";
  -    rev = "v${version}";
  -    hash = "sha256-IlBwlVQ/v+vJmCWNbFZKGL6a9K09z4AYrPm3kwaA/nI=";
  +    # no tag for 0.7.1
  +    rev = "2d8fd04f68a124d0f3df7b81584accc3270b1afc";
  +    hash = "sha256-1EXXXflhDeU+erdI+NsWxSX76ooDTl3+MyQwRzm2xV0=";
     };
   
     propagatedBuildInputs = [
  +    azure-core
       aiodns
       aiohttp
       certifi
  
positive.code: { lib
  , aiodns
  , aiohttp
  , buildPythonPackage
  , certifi
  , fetchFromGitHub
  
negative.code: 
  buildPythonPackage rec {
    pname = "msrest";
    version = "0.7.1";
    format = "setuptools";
  
    disabled = pythonOlder "3.7";
  