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