What causes "creating v6 client: %w" in grafana/k6?

Inspect the wrapped error with errors.Unwrap / %w chaining to find the real cause

creating v6 client: %w

Error message

creating v6 client: %w

What it means

provisioning.NewClient (internal/cloudapi/provisioning/client.go:54) wraps the failure of the embedded v6.NewClient. Today v6.NewClient only fails on an empty token, which the caller has already guarded, so this wrapper is defensive and effectively unreachable; if it ever fires, the wrapped error (%w) carries the real cause.

Source

Thrown at internal/cloudapi/provisioning/client.go:54

// NewClient returns a new provisioning Client. It internally constructs
// both a k6cloud.APIClient (for provisioning endpoints) and a v6.Client
// (for v6 operations like FetchTest). The stackID identifies the
// Grafana Cloud stack and is required for the stack-scoped requests.
func NewClient(
	logger logrus.FieldLogger,
	token, host, version string,
	stackID int64,
	timeout time.Duration,
) (*Client, error) {
	if token == "" {
		return nil, fmt.Errorf("token is required to create provisioning API client")
	}

	cfg := clientcfg.New(host, version, "k6 Cloud API (provisioning).", timeout)

	v6c, err := v6.NewClient(logger, token, host, version, timeout)
	if err != nil {
		return nil, fmt.Errorf("creating v6 client: %w", err)
	}

	c := &Client{
		apiClient: k6cloud.NewAPIClient(cfg),
		v6Client:  v6c,
		token:     token,
		stackID:   stackID,
		host:      host,
		version:   version,
		logger:    logger,
	}
	// Propagate the stack ID to the embedded v6 client. v6.SetStackID
	// validates that it fits the int32 the SDK's X-Stack-Id requires —
	// that is the single place the int32 boundary is enforced.
	if err := c.v6Client.SetStackID(stackID); err != nil {
		return nil, err
	}
	// The provisioning endpoints carry the stack ID as a decimal-string

View on GitHub (pinned to 93accf6570)

Solutions

Inspect the wrapped error with errors.Unwrap / %w chaining to find the real cause
Check the k6 version and the v6.NewClient guard in that version
If adding new validation to v6.NewClient, mirror it (or pre-validate) in provisioning.NewClient to keep the message actionable

Defensive patterns

Strategy: try-catch

Type guard

func isV6ConstructionFailure(err error) bool {
	return err != nil && strings.Contains(err.Error(), "creating v6 client")
}

Try / catch

client, err := provisioning.NewClient(...)
if err != nil {
	if inner := errors.Unwrap(err); inner != nil {
		log.Printf("v6 client failure cause: %v", inner)
	}
	return err
}

Prevention

Always unwrap chained construction errors before diagnosing
When adding validation to one constructor, mirror it in wrappers to keep messages actionable

When it happens

Trigger: v6.NewClient returning an error during provisioning client construction — only possible if the two guards diverge in a future version (e.g. v6 starts validating host or token format).

Common situations: Version drift after refactoring one client's constructor but not the other; effectively never seen in the wild today.

Related errors

AI-assisted analysis of grafana/k6@93accf6570 (2026-08-15). Data as JSON: /api/errors/0f2c5b0f405791f1. Report an issue: GitHub.