kubernetes/kops · error

error re-marshaling manifest: %v

Error message

error re-marshaling manifest: %v

What it means

ToYAML re-serializes each Object in the manifest back to YAML and joins documents. If any individual object's ToYAML (yaml.Marshal of its data map) fails, the multi-document write is aborted with this error. This surfaces Marshal failures such as unencodable values inside the parsed data.

Source

Thrown at pkg/kubemanifest/manifest.go:119

			return true
		}
	}
	return false
}

// ToYAML serializes a list of objects back to bytes; it is the opposite of LoadObjectsFrom
func (l ObjectList) ToYAML() ([]byte, error) {
	yamlSeparator := []byte("\n---\n\n")
	var yamls [][]byte
	for _, object := range l {
		// Don't serialize empty objects - they confuse yaml parsers
		if object.IsEmptyObject() {
			continue
		}

		y, err := object.ToYAML()
		if err != nil {
			return nil, fmt.Errorf("error re-marshaling manifest: %v", err)
		}

		yamls = append(yamls, y)
	}

	return bytes.Join(yamls, yamlSeparator), nil
}

func (m *Object) ToYAML() ([]byte, error) {
	b, err := yaml.Marshal(m.data)
	if err != nil {
		return nil, fmt.Errorf("error marshaling manifest to yaml: %w", err)
	}
	return b, nil
}

func (m *Object) MarshalJSON() ([]byte, error) {
	b, err := json.Marshal(m.data)

View on GitHub (pinned to 4c8573c808)

Solutions

1. Inspect what was inserted into the object's data map; only plain YAML-representable values (maps, slices, scalars) are allowed
2. Use the wrapped error to identify the unserializable value's path
3. Re-parse the manifest from disk to reset the data to clean values
4. Fix the transformation code (e.g. addPodSpecLabels-style rewriters) to avoid injecting non-basic types

// verify data contains only YAML-safe values before ToYAML
func yamlSafe(v interface{}) bool {
	switch t := v.(type) {
	case map[string]interface{}:
		for _, vv := range t { if !yamlSafe(vv) { return false } }
	case []interface{}:
		for _, vv := range t { if !yamlSafe(vv) { return false } }
	case string, bool, int, int64, float64, nil:
		return true
	default:
		return false
	}
	return true
}

y, err := manifest.ToYAML()
if err != nil {
	return fmt.Errorf("manifest rewrite produced unserializable data: %w", err)
}

When it happens

Trigger: Calling ToYAML (or its callers Replace/Build) after the manifest data map contains values that yaml.Marshal cannot serialize — e.g. channels, funcs, or cyclic structures injected programmatically into the Object's data.

Common situations: Programmatic manifest mutation that inserted unsupported Go values into the object map; corrupted in-memory data after a buggy transformation.

Related errors

• error parsing addons or manifest: %v
• failed to parse objects: %w
• failed to parse objects: %w
• error marshaling yaml: %v
• error writing yaml to stdout: %v

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/0cd7f970a0e94934. Report an issue: GitHub.