argoproj/argo-workflows · error

requires either selector or workflow

Error message

requires either selector or workflow

What it means

`argo stop` needs a target: either workflow name(s) as positional args or a selector (--field-selector / --node-field-selector via stopArgs.hasSelector()). The Args validator at cmd/argo/commands/stop.go:59 rejects invocations with neither, as stopping with no target would be ambiguous.

Source

Thrown at cmd/argo/commands/stop.go:59

		Example: `# Stop a workflow:

  argo stop my-wf

# Stop the latest workflow:

  argo stop @latest

# Stop multiple workflows by label selector

  argo stop -l workflows.argoproj.io/test=true

# Stop multiple workflows by field selector

  argo stop --field-selector metadata.namespace=argo
`,
		Args: func(cmd *cobra.Command, args []string) error {
			if len(args) == 0 && !stopArgs.hasSelector() {
				return errors.New("requires either selector or workflow")
			}
			return nil
		},
		RunE: func(cmd *cobra.Command, args []string) error {
			ctx := cmd.Context()
			ctx, apiClient, err := client.NewAPIClient(ctx)
			if err != nil {
				return err
			}
			serviceClient := apiClient.NewWorkflowServiceClient(ctx)
			stopArgs.namespace = client.Namespace(ctx)

			return stopWorkflows(ctx, serviceClient, stopArgs, args)
		},
	}
	command.Flags().StringVar(&stopArgs.message, "message", "", "Message to add to previously running nodes")
	command.Flags().StringVar(&stopArgs.nodeFieldSelector, "node-field-selector", "", "selector of node to stop, eg: --node-field-selector inputs.parameters.myparam.value=abc")
	command.Flags().StringVarP(&stopArgs.labelSelector, "selector", "l", "", "Selector (label query) to filter on, not including uninitialized ones, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2)")

View on GitHub (pinned to 35bff19146)

Solutions

1. Pass workflow names: `argo stop my-wf`
2. Or use a selector for bulk stops: `argo stop --field-selector metadata.namespace=argo`
3. In scripts, verify the args array is non-empty before invoking argo stop

Example fix

// before
argo stop   # no target
// after
argo stop --field-selector metadata.namespace=argo

if [ ${#WF_ARGS[@]} -eq 0 ] && [ -z "$FIELD_SELECTOR" ]; then
  echo "argo stop: requires either selector or workflow" >&2; exit 2
fi

When it happens

Trigger: Running `argo stop` with no arguments and no selector flags, e.g. expecting `argo stop` to stop workflows in the current namespace.

Common situations: Confusion with kubectl-style 'apply to namespace' mental models; scripts where the workflow list was empty so args vanished; omitting --field-selector when intending a bulk stop.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• requires either node field selector or workflow
• requires either node field selector or workflow
• --since-time and --since cannot be used together
• cannot combine --from with file arguments
• cannot watch more than one workflow

AI-assisted analysis of argoproj/argo-workflows@35bff19146 (2026-09-03). Data as JSON: /api/errors/2ff1dab14eab12f8. Report an issue: GitHub.