grafana/k6 · error

stack value is required but it was not passed or is empty

Error message

stack value is required but it was not passed or is empty

What it means

In `k6 cloud login`, when either --token or --stack is supplied non-interactively, BOTH must be supplied and non-empty. This branch fires when the token was provided (or a stack value arrived empty) but the stack input is invalid or empty — non-interactive login is all-or-nothing by design, because there is no prompt to fill the gap.

Source

Thrown at internal/cmd/cloud_login.go:107

	show := getNullBool(cmd.Flags(), "show")
	reset := getNullBool(cmd.Flags(), "reset")
	tokenInput := getNullString(cmd.Flags(), "token")
	stackInput := getNullString(cmd.Flags(), "stack")

	switch {
	case reset.Valid:
		newCloudConf.Token = null.StringFromPtr(nil)
		newCloudConf.StackID = null.IntFromPtr(nil)
		newCloudConf.StackURL = null.StringFromPtr(nil)
		newCloudConf.DefaultProjectID = null.IntFromPtr(nil)
		printToStdout(c.globalState, "\nToken and stack info have been reset.\n")
	case show.Bool:
		printConfig(c.globalState, newCloudConf)
		return nil
	case tokenInput.Valid || stackInput.Valid:
		if !stackInput.Valid || stackInput.String == "" {
			return errors.New("stack value is required but it was not passed or is empty")
		}
		if !tokenInput.Valid || tokenInput.String == "" {
			return errors.New("token value is required but it was not passed or is empty")
		}
		err := authenticateUserToken(c.globalState, &newCloudConf, currentJSONConfigRaw, tokenInput.String, stackInput.String)
		if err != nil {
			return err
		}
	default:
		gs := c.globalState

		userinfo, err := promptUserAuthForm(gs)
		if err != nil {
			return err
		}

		err = authenticateUserToken(gs, &newCloudConf, currentJSONConfigRaw,
			userinfo.token, userinfo.stack)

View on GitHub (pinned to 93accf6570)

Solutions

1. Supply both flags together: `k6 cloud login --token <TOKEN> --stack <slug-or-URL>`
2. Or drop both flags and use the interactive form `k6 cloud login`, which prompts for each field
3. If the stack comes from a variable, assert it is non-empty before invoking the command

Example fix

# before
k6 cloud login --token "$K6_CLOUD_TOKEN"   # ERR: stack value is required

# after
k6 cloud login --token "$K6_CLOUD_TOKEN" --stack "my-team"
# or: k6 cloud login   (interactive prompts)

# non-interactive login requires BOTH values; assert before invoking
: "${K6_CLOUD_TOKEN:?token required}" 
: "${K6_CLOUD_STACK:?stack required}" 
k6 cloud login --token "$K6_CLOUD_TOKEN" --stack "$K6_CLOUD_STACK"

When it happens

Trigger: `k6 cloud login --token <TOKEN>` without --stack; or a --stack flag resolving to an empty string while --token is set (e.g. an empty value from a wrapper script variable).

Common situations: CI login scripts that pass the token via flag but expect the stack from config; a $K6_CLOUD_STACK shell variable that is empty in the job, interpolated into the flag as an empty string.

Related errors

• Run `k6 cloud login` to authenticate, or check the docs for
• token value is required but it was not passed or is empty
• access token not configured
• token cannot be empty
• stack cannot be empty

AI-assisted analysis of grafana/k6@93accf6570 (2026-08-15). Data as JSON: /api/errors/4b35cc7c32026f2d. Report an issue: GitHub.