anchor.diff:  
   let
     cfg = config.services.chrony;
  +  chronyPkg = cfg.package;
   
     stateDir = cfg.directory;
     driftFile = "${stateDir}/chrony.drift";
  
positive.code:         description = ''
            Whether to synchronise your machine's time using chrony.
            Make sure you disable NTP if you enable this service.
          '';
        };
  
  
negative.code:   config = mkIf cfg.enable {
      meta.maintainers = with lib.maintainers; [ thoughtpolice ];
  
      environment.systemPackages = [ chronyPkg ];
  
      users.groups.chrony.gid = config.ids.gids.chrony;
  
  