anchor.diff:  { stdenv
   , buildPythonPackage
   , fetchPyPi
  +
  +, pythonPackages
   }:
  +
  +let
  +  inherit (pythonPackages)
  +    pythonAtLeast;
  +in
   
   buildPythonPackage rec {
     name = "backports_abc-${version}";
  
positive.code:     sha256 = "8b3e4092ba3d541c7a2f9b7d0d9c0275b21c6a01c53a61c731eba6686939d0a5";
    };
  
    doCheck = true;
  
    meta = with stdenv.lib; {
  
negative.code:     platforms = with platforms;
        x86_64-linux;
    };
  }
  