ahmetb/kubectx · error

failed to encode file %d: %w

Error message

failed to encode file %d: %w

What it means

In the Save loop, re-encoding file i's in-memory config back to YAML failed after a successful Reset. Encode errors are rare — usually a programmatically built node tree that cannot serialize — and the file was already truncated, so its previous content is lost from this point on.

Source

Thrown at internal/kubeconfig/kubeconfig.go:211

	if len(elements) == 0 {
		return nil, nil
	}
	seqNode := &yaml.Node{Kind: yaml.SequenceNode, Tag: "!!seq"}
	for _, elem := range elements {
		seqNode.Content = append(seqNode.Content, elem.YNode())
	}
	return yaml.NewRNode(seqNode), nil
}

func (k *Kubeconfig) Save() error {
	for i := range k.files {
		if err := k.files[i].f.Reset(); err != nil {
			return fmt.Errorf("failed to reset file %d: %w", i, err)
		}
		enc := yaml.NewEncoder(k.files[i].f)
		enc.SetIndent(0)
		if err := enc.Encode(k.files[i].config.YNode()); err != nil {
			return fmt.Errorf("failed to encode file %d: %w", i, err)
		}
		if err := enc.Close(); err != nil {
			return fmt.Errorf("failed to close encoder for file %d: %w", i, err)
		}
	}
	return nil
}

View on GitHub (pinned to 12ad6fb22e)

Solutions

1. Keep a backup of kubeconfig files before operations that mutate them
2. Inspect the N-th file: after this error it may be partially/empty written — restore from backup
3. Report the bug if it reproduces, since valid configs should always re-encode

When it happens

Trigger: Thrown at internal/kubeconfig/kubeconfig.go:211 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ahmetb/kubectx@12ad6fb22e (2026-09-02). Data as JSON: /api/errors/ffed87b9b4e768b1. Report an issue: GitHub.