abiosoft/colima · error

unexpected error during yaml node traversal: %w

Error message

unexpected error during yaml node traversal: %w

What it means

encodeYAML (util/yamlutil/yaml.go:95) roundtrips each value: bytes just produced by yaml.Marshal are immediately Unmarshaled into a yaml.Node; this error wraps that Unmarshal. Since the input is output of the same yaml.v3 library, this failure is effectively an unreachable internal invariant — it would require Marshal to emit invalid YAML. Encountering it points to memory corruption or an inconsistent yaml.v3 version mismatch in the build.

Source

Thrown at util/yamlutil/yaml.go:95

				continue
			}
		}

		// nil slices are converted to untyped nil to encode as `null` instead of `[]`.
		// this preserves nil vs empty slice distinction when the yaml is loaded back.
		if v := reflect.ValueOf(val); v.Kind() == reflect.Slice && v.IsNil() {
			val = nil
		}

		// lazy way, delegate node construction to the yaml library via a roundtrip.
		// no performance concern as only one file is being read
		b, err := yaml.Marshal(val)
		if err != nil {
			return nil, fmt.Errorf("unexpected error nested value encoding: %w", err)
		}
		var newNode yaml.Node
		if err := yaml.Unmarshal(b, &newNode); err != nil {
			return nil, fmt.Errorf("unexpected error during yaml node traversal: %w", err)
		}

		if l := len(newNode.Content); l != 1 {
			return nil, fmt.Errorf("unexpected error during yaml node traversal: doc has multiple children of len %d", l)
		}
		*node = *newNode.Content[0]
	}

	b, err := encode(root)
	if err != nil {
		return nil, fmt.Errorf("error encoding yaml file: %w", err)
	}

	return b, nil
}

func traverseConfig(parentKey string, s any, vals map[string]any) {
	typ := reflect.TypeOf(s)

View on GitHub (pinned to c3a5f9184d)

Solutions

1. Rebuild with the stock gopkg.in/yaml.v3 dependency (go mod tidy, remove vendored forks)
2. Report upstream — include the wrapped underlying error, which identifies what yaml rejected
3. If it flaps intermittently, check for concurrent config mutation and guard saves with a mutex
4. Reinstall the official binary to rule out local corruption

if err := util.Save(cfg, file); err != nil {
    if strings.Contains(err.Error(), "yaml node traversal") {
        // internal invariant: capture diagnostics, then reinstall/report upstream
    }
    return err
}

When it happens

Trigger: No legitimate runtime input reaches this line; only a corrupted process, a patched/incompatible gopkg.in/yaml.v3 replacement, or a bug in a vendored fork of the yaml library triggers it.

Common situations: Vendored forks of yaml.v3 with divergent behavior; binary corruption; experimental reflect-based value mutation happening concurrently during config save (data race producing garbage bytes).

Related errors

• unexpected error during yaml node traversal: doc has multipl
• embedded default config is invalid yaml: %w
• unexpected error during yaml decode: doc has multiple childr
• error traversing yaml node: %w
• error encoding yaml file: %w

AI-assisted analysis of abiosoft/colima@c3a5f9184d (2026-08-15). Data as JSON: /api/errors/6ca5fd19b81450fc. Report an issue: GitHub.