GoogleContainerTools/skaffold · error

transforming skaffold config: %w

Error message

transforming skaffold config: %w

What it means

UpgradeTo performs stepwise upgrades by repeatedly calling cfg.Upgrade() until the config reaches the target version. If any single-step transformation fails (a bug in a versioned Upgrade implementation or an invalid intermediate config), the error is wrapped as 'transforming skaffold config: %w'.

Source

Thrown at pkg/skaffold/schema/versions.go:419

		if currentVersion.NE(targetVersion) {
			upgradeNeeded = true
		}
		if currentVersion.GT(targetVersion) {
			return nil, fmt.Errorf("config version %q is more recent than target version %q: upgrade Skaffold", cfg.GetVersion(), toVersion)
		}
	}
	if !upgradeNeeded {
		return configs, nil
	}
	log.Entry(context.TODO()).Debugf("config version out of date: upgrading to latest %q", toVersion)
	var err error
	var upgraded []util.VersionedConfig
	for _, cfg := range configs {
		for cfg.GetVersion() != toVersion {
			cfg, err = cfg.Upgrade()
			if err != nil {
				return nil, fmt.Errorf("transforming skaffold config: %w", err)
			}
		}
		upgraded = append(upgraded, cfg)
	}
	return upgraded, nil
}

View on GitHub (pinned to a1189de023)

Solutions

1. Run `skaffold fix` to see which transformation step fails, then hand-migrate the reported fields in skaffold.yaml to the target schema.
2. Update the Skaffold binary — newer releases often fix broken upgrade steps for older configs.
3. Validate the skaffold.yaml against the source version schema to remove unsupported/renamed fields before upgrading.
4. If developing Skaffold itself, inspect the Upgrade() implementation for the failing intermediate version and fix or guard it.

Example fix

// before: failing old field
build:
  artifacts:
  - imageName: myapp

// after (renamed by schema migration)
build:
  artifacts:
  - image: myapp

// pre-validate config parses on its declared version
if _, err := schema.ParseConfig(cfg.GetVersion(), yamlBytes, false); err != nil {
	return fmt.Errorf("config invalid for %s, fix fields before upgrade: %w", cfg.GetVersion(), err)
}

upgraded, err := schema.UpgradeTo(configs, latest.Version)
if err != nil {
	var stepErr error
	if errors.As(err, &stepErr) {}
	log.Errorf("upgrade failed at a transformation step: %v — run `skaffold fix` and inspect the reported fields", err)
	return err
}

When it happens

Trigger: UpgradeTo(configs, toVersion) where cfg.Upgrade() returns an error on one of the intermediate steps of the chain currentVersion -> ... -> toVersion. This can also occur if the version chain never terminates because GetVersion() never equals toVersion and Upgrade() keeps returning an unchanged config with an error.

Common situations: Parsing an old skaffold.yaml whose fields cannot be mechanically migrated (deprecated/removed fields with no automatic equivalent) during `skaffold fix` or normal config load/upgrade; also triggered by a mismatch where Upgrade() returns a config whose version does not advance.

Related errors

• the following versions are incompatible with target version
• INSPECT_PROFILE_NOT_FOUND_ERR
• cannot resolve active Kubernetes context - multiple contexts
• CONFIG_UNKNOWN_API_VERSION_ERR
• missing apiVersion

AI-assisted analysis of GoogleContainerTools/skaffold@a1189de023 (2026-09-05). Data as JSON: /api/errors/15ba4f2c21fa72e7. Report an issue: GitHub.