anchor.diff:      ${cfg.extraConfig}
     '';
   
  -  chronyFlags = "-n -m -u chrony -f ${configFile} ${toString cfg.extraFlags}";
  -
  +  chronyFlags = "-m -u chrony -f ${configFile} ${toString cfg.extraFlags}";
   in
  -
   {
  -
  -  ###### interface
  -
     options = {
  -
       services.chrony = {
  -
         enable = mkOption {
           default = false;
           description = ''
  
positive.code: with lib;
  
  let
  
    stateDir = "/var/lib/chrony";
  
    keyFile = "/etc/chrony.keys";
  
    cfg = config.services.chrony;
  
    configFile = pkgs.writeText "chrony.conf" ''
      ${concatMapStringsSep "\n" (server: "server " + server) cfg.servers}
  
negative.code:         description = "Extra flags passed to the chronyd command.";
        };
      };
    };
  
    config = mkIf cfg.enable {
      environment.systemPackages = [ pkgs.chrony ];
  
      users.groups = singleton
  