slimtoolkit/slim · error

missing command

Error message

missing command

What it means

runControlCommand implements the `sensor control <command>` CLI. A control invocation must include a command name as os.Args[2]; if the process was invoked with fewer args, there is no command to dispatch and it returns this error.

Source

Thrown at pkg/app/sensor/app.go:305

func dumpAppBom() {
	info := appbom.Get()
	if info == nil {
		return
	}

	var out bytes.Buffer
	encoder := json.NewEncoder(&out)
	encoder.SetEscapeHTML(false)
	encoder.SetIndent(" ", " ")
	_ = encoder.Encode(info)
	fmt.Printf("%s\n", out.String())
}

// sensor control <stop-target-app|wait-for-event|change-log-level|...>
func runControlCommand(ctx context.Context) error {
	if len(os.Args) < 3 {
		return errors.New("missing command")
	}

	cmd := control.Command(os.Args[2])

	switch cmd {
	case control.StopTargetAppCommand:
		if err := control.ExecuteStopTargetAppCommand(ctx, *commandsFile); err != nil {
			return fmt.Errorf("error stopping target app: %w", err)
		}

	case control.WaitForEventCommand:
		if len(os.Args) < 4 {
			return errors.New("missing event name")
		}
		if err := control.ExecuteWaitEvenCommand(ctx, eventsFilePath(), event.Type(os.Args[3])); err != nil {
			return fmt.Errorf("error waiting for sensor event: %w", err)
		}

View on GitHub (pinned to 81940d17fa)

Solutions

1. Pass the control subcommand: sensor control stop-target-app
2. Check the calling script/hook builds argv correctly (command at index 2)
3. Run `sensor control` help/docs to see valid subcommands

Example fix

// before
sensor control
// after
sensor control stop-target-app

if len(os.Args) < 3 { return errors.New("usage: sensor control <command>") }

if err := runControlCommand(ctx); err != nil && strings.Contains(err.Error(), "missing command") {
  fmt.Fprintln(os.Stderr, "usage: sensor control <stop-target-app|wait-for-event|...>")
  os.Exit(2)
}

When it happens

Trigger: Running `sensor control` (or `sensor control` with only the mode arg) without a subcommand such as stop-target-app or wait-for-event.

Common situations: Hand-typing the control command and forgetting the subcommand; a script building the command line drops an argument; lifecycle hook configured with an empty command list.

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

• missing event name
• unknown sensor mode
• error stopping target app: %w
• error waiting for sensor event: %w
• unknown command: %s

AI-assisted analysis of slimtoolkit/slim@81940d17fa (2026-08-31). Data as JSON: /api/errors/0772e97cf54fef1b. Report an issue: GitHub.