docker/cli · error

type is empty: must be one of "%s"

Error message

type is empty: must be one of "%s"

What it means

Error "type is empty: must be one of "%s"" thrown in docker/cli.

Source

Thrown at cli/command/system/inspect.go:69

type inspectOptions struct {
	format     string
	objectType objectType
	size       bool
	ids        []string
}

// newInspectCommand creates a new cobra.Command for `docker inspect`
func newInspectCommand(dockerCLI command.Cli) *cobra.Command {
	var opts inspectOptions

	cmd := &cobra.Command{
		Use:   "inspect [OPTIONS] NAME|ID [NAME|ID...]",
		Short: "Return low-level information on Docker objects",
		Args:  cli.RequiresMinArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			opts.ids = args
			if cmd.Flags().Changed("type") && opts.objectType == "" {
				return fmt.Errorf(`type is empty: must be one of "%s"`, strings.Join(allTypes, `", "`))
			}
			return runInspect(cmd.Context(), dockerCLI, opts)
		},
		// TODO(thaJeztah): should we consider adding completion for common object-types? (images, containers?)
		ValidArgsFunction:     completeObjectNames(dockerCLI),
		DisableFlagsInUseLine: true,
	}

	flags := cmd.Flags()
	flags.StringVarP(&opts.format, "format", "f", "", flagsHelper.InspectFormatHelp)
	flags.StringVar(&opts.objectType, "type", "", "Only inspect objects of the given type")
	flags.BoolVarP(&opts.size, "size", "s", false, "Display total file sizes if the type is container")

	_ = cmd.RegisterFlagCompletionFunc("type", completion.FromList(allTypes...))

	return cmd
}

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at cli/command/system/inspect.go:69 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/3a1e7fe819dd998c.json. Report an issue: GitHub.