anchor.diff:  { lib
  +, stdenv
   , buildPythonPackage
   , fetchFromGitHub
   , pythonOlder
  
positive.code:     owner = "Textualize";
      repo = pname;
      rev = "v${version}";
      sha256 = "sha256-DW6cKJ5bXZdHGzgbYzTS+ryjy71dU9Lcy+egMXL30F8=";
    };
  
    nativeBuildInputs = [ poetry-core ];
  
negative.code: 
  buildPythonPackage rec {
    pname = "rich";
    version = "12.5.1";
    format = "pyproject";
    disabled = pythonOlder "3.6";
  
  