anchor.diff:  { paths
   , configuration
  +, evaluator ? (x: x)
   }:
   
   with builtins;
  
positive.code:     );
    };
  
    eval = lib.evalModules {
      specialArgs.paths = pathAttrs';
      specialArgs.pathsFile = pathsFile;
      modules = [
  
negative.code:       "${pathAttrs'.nixpkgs}/nixos/modules/misc/nixpkgs.nix"
      ];
    };
  )
  