anchor.diff:      "-alertmanager.notification-queue-capacity=${toString cfg.alertmanagerNotificationQueueCapacity}"
       "-alertmanager.timeout=${toString cfg.alertmanagerTimeout}s"
     ] ++
  -    (optional (cfg.alertmanagerURL != []) "-alertmanager.url=${concatStringsSep "," cfg.alertmanagerURL}") ++
  -    (optional (cfg.webExternalUrl != null) "-web.external-url=${cfg.webExternalUrl}");
  +  optional (cfg.alertmanagerURL != []) "-alertmanager.url=${concatStringsSep "," cfg.alertmanagerURL}" ++
  +  optional (cfg.webExternalUrl != null) "-web.external-url=${cfg.webExternalUrl}";
   
     # This becomes the main config file for Prometheus 2
     promConfig2 = {
  
positive.code:         wantedBy = [ "multi-user.target" ];
          after    = [ "network.target" ];
          serviceConfig = {
          ExecStart = "${cfg.package}/bin/prometheus" +
            optionalString (length cmdlineArgs != 0) (" \\\n  " +
              concatStringsSep " \\\n  " cmdlineArgs);
            User = promUser;
            Restart  = "always";
            WorkingDirectory = /var/lib/prometheus;
  
negative.code:     "--alertmanager.notification-queue-capacity=${toString cfg2.alertmanagerNotificationQueueCapacity}"
      "--alertmanager.timeout=${toString cfg2.alertmanagerTimeout}s"
    ] ++
    optional (cfg2.webExternalUrl != null) "--web.external-url=${cfg2.webExternalUrl}";
  
    promTypes.globalConfig = types.submodule {
      options = {
  