anchor.diff:  let
   
     cfg = config.systemd;
  -
  -  systemd = cfg.package;
   
     inherit (systemdUtils.lib)
       generateUnits
  
positive.code:       ]);
      };
  
      environment.systemPackages = [ systemd ];
  
      environment.etc = let
        # generate contents for /etc/systemd/system-${type} from attrset of links and packages
  
negative.code: 
      system.build.units = cfg.units;
  
      system.nssModules = [ cfg.package.out ];
      system.nssDatabases = {
        hosts = (mkMerge [
          (mkOrder 400 ["mymachines"]) # 400 to ensure it comes before resolve (which is mkBefore'd)
  