portForward[ ] of config with name ' ' is empty, Please…

Error message

portForward[%d] of config with name '%s' is empty, Please check if it has valid values

What it means

Schema defaults processing (Set) validates each portForward entry after applying defaults. A nil entry in the PortForward list is invalid configuration, so it errors identifying the index and config name, telling the user to supply valid portForward values.

Solutions

Open skaffold.yaml and fix or remove the empty portForward entry at the reported index
Validate the merged result of profiles/overlays — an override may be nulling the entry
Run `skaffold diagnose` to catch the malformed config before running
Ensure programmatic config builders always append initialized &latest.PortForward{...} values

Example fix

# before: empty portForward entry
portForward:
  -
# after
portForward:
  - localPort: 8080
    port: 80
    resourceType: service
    resourceName: web

Defensive patterns

Strategy: validation

Validate before calling

for i, pf := range cfg.PortForward {
    if pf == nil { return fmt.Errorf("portForward[%d] is nil in skaffold.yaml", i) }
}
// run before passing config to defaults.Set

Try / catch

if err := defaults.Set(cfg); err != nil {
    var pe *fmt.Errorf
    if strings.Contains(err.Error(), "is empty") { return fmt.Errorf("malformed portForward entry: %v", err) }
    return err
}

Prevention

Lint skaffold.yaml (skaffold diagnose / schema validation) after every edit
Check profile merges and overlays don't null out portForward items
Never append nil pointers when building configs programmatically

When it happens

Trigger: Calling Set (directly or via fix/withFallbackConfig/processEachConfig) on a config whose c.PortForward slice contains a nil element — i.e. an empty portForward item in skaffold.yaml or a programmatically built config with a nil pointer.

Common situations: A portForward entry in skaffold.yaml left empty/malformed (e.g. `- ` with no fields after merging config fragments or applying profiles), or generated configs where a portForward object failed to deserialize.

Related errors

AI-assisted analysis of GoogleContainerTools/skaffold@a1189de023 (2026-09-05). Data as JSON: /api/errors/40fd0f9679d30a1b. Report an issue: GitHub.

Appendix: source

Thrown at pkg/skaffold/schema/defaults/defaults.go:111

		setDefaultCloudBuildMavenImage,
		setDefaultCloudBuildGradleImage,
		setDefaultCloudBuildKanikoImage,
		setDefaultCloudBuildPackImage,
		setDefaultCloudBuildKoImage,
	)

	if err := withClusterConfig(c,
		setDefaultClusterNamespace,
		setDefaultClusterTimeout,
		setDefaultClusterPullSecret,
		setDefaultClusterDockerConfigSecret,
	); err != nil {
		return err
	}

	for i, pf := range c.PortForward {
		if pf == nil {
			return fmt.Errorf("portForward[%d] of config with name '%s' is empty, Please check if it has valid values", i, c.Metadata.Name)
		}
		setDefaultLocalPort(pf)
		setDefaultAddress(pf)
	}

	setDefaultTestWorkspace(c)
	return nil
}

func setHelmDefaults(c *latest.SkaffoldConfig) error {
	if c.Deploy.LegacyHelmDeploy == nil {
		return nil
	}

	if c.Deploy.LegacyHelmDeploy.Concurrency == nil {
		defaultConcurrency := 1
		c.Deploy.LegacyHelmDeploy.Concurrency = &defaultConcurrency
	}

View on GitHub (pinned to a1189de023)