What causes "failed to update workflow template: %w" in argoproj/argo-workflows?

Inspect the wrapped error — validation errors list the offending field; fix the YAML/spec accordingly.

failed to update workflow template: %w

Error message

failed to update workflow template: %w

What it means

After fetching the existing template's ResourceVersion, updateWorkflowTemplates calls UpdateWorkflowTemplate on the API server. If that call fails, the error is wrapped as `failed to update workflow template: %w`. The inner error carries the actual API failure — typically a validation rejection, conflict, or permission problem.

Source

Thrown at cmd/argo/commands/template/update.go:76

	for _, wftmpl := range workflowTemplates {
		if wftmpl.Namespace == "" {
			wftmpl.Namespace = client.Namespace(ctx)
		}
		current, err := serviceClient.GetWorkflowTemplate(ctx, &workflowtemplatepkg.WorkflowTemplateGetRequest{
			Name:      wftmpl.Name,
			Namespace: wftmpl.Namespace,
		})
		if err != nil {
			return fmt.Errorf("failed to get existing workflow template %q to update: %w", wftmpl.Name, err)
		}
		wftmpl.ResourceVersion = current.ResourceVersion
		updated, err := serviceClient.UpdateWorkflowTemplate(ctx, &workflowtemplatepkg.WorkflowTemplateUpdateRequest{
			Namespace: wftmpl.Namespace,
			Template:  &wftmpl,
		})
		if err != nil {
			return fmt.Errorf("failed to update workflow template: %w", err)
		}
		printWorkflowTemplate(updated, cliOpts.output.String())
	}
	return nil
}

View on GitHub (pinned to 35bff19146)

Solutions

Inspect the wrapped error — validation errors list the offending field; fix the YAML/spec accordingly.
Re-fetch the template and retry if the error is a conflict (stale ResourceVersion).
Verify RBAC: the caller needs `update` on `workflowtemplates` in the target namespace.
Run `argo lint` on the file before updating to catch spec errors client-side.

Example fix

// before
argo template update bad.yaml   # server rejects invalid spec
// after
argo lint bad.yaml              # catch validation first
argo template update bad.yaml

Defensive patterns

Strategy: retry

Validate before calling

argo lint file.yaml  # validate spec before updating

Try / catch

for i := 0; i < 3; i++ {
    _, err := client.UpdateWorkflowTemplate(ctx, req)
    if err == nil { break }
    if apierrors.IsConflict(err) { re-fetch resourceVersion; continue }
    return err
}

Prevention

Re-fetch the template immediately before update to get a fresh ResourceVersion
Run argo lint on the file before every update
Check for concurrent writers (CI + humans) on the same template
Verify update RBAC for the caller

When it happens

Trigger: The modified template fails schema/validation checks (invalid spec); a concurrent writer changed the ResourceVersion causing a conflict; RBAC denies `update workflowtemplates`; template is immutable in some field (e.g. changing certain metadata).

Common situations: Editing a spec with a schema error (bad template syntax) caught server-side; two operators updating the same template simultaneously; CI service account lacking update RBAC.

Related errors

AI-assisted analysis of argoproj/argo-workflows@35bff19146 (2026-09-03). Data as JSON: /api/errors/3b4bcd7d9719da69. Report an issue: GitHub.