anchor.diff:    meta = {
       description = "Export Prometheus metrics from DMARC reports";
       homepage = "https://github.com/jgosmann/dmarc-metrics-exporter";
  +    changelog = "https://github.com/jgosmann/dmarc-metrics-exporter/blob/v${version}/CHANGELOG.rst";
       license = lib.licenses.mit;
       maintainers = with lib.maintainers; [ ma27 ];
     };
  
positive.code: { lib
  , python3
  , fetchpatch
  }:
  
  python3.pkgs.buildPythonApplication rec {
    pname = "dmarc-metrics-exporter";
    version = "0.5.1";
  
    disabled = python3.pythonOlder "3.7";
  
  
negative.code: 
    src = python3.pkgs.fetchPypi {
      inherit pname version;
      sha256 = "70f39b373ead42acb8caf56040f7ebf13ab67aea505511025c09ecf4560f8b1b";
    };
  
    postPatch = ''
      substituteInPlace pyproject.toml \
        --replace '"^' '">='
    '';
  
  