anchor.diff: -{ stdenv
  -, lib
  +{ lib
  +, stdenv
   , buildPythonPackage
   , fetchPypi
   , pyannotate
  
positive.code:   propagatedBuildInputs = [
      pyannotate
    ];
  
    # Module has no tests
    doCheck = false;
  
negative.code: 
    src = fetchPypi {
      inherit pname version;
      hash = "sha256-0NpMPYcqfVeWrIUBbKodo4rpAr69x1nhtsD2+LWAJ0E=";
    };
  
    buildInputs = [
  