JanDeDobbeleer/oh-my-posh · error

failed to parse data file: %w

Error message

failed to parse data file: %w

What it means

After reading the data file, decodeDataRoot unmarshals content based on file extension. For .json/.jsonc files, JSON comments are stripped and json.Unmarshal runs; on failure this wrapped error is returned. The file was readable but its contents are not valid JSON (or JSONC after comment stripping).

Source

Thrown at src/config/data.go:177

	if err != nil {
		return nil, err
	}

	return dataFromRoot(root)
}

// decodeDataRoot decodes raw into a generic map of raw JSON messages,
// dispatching on ext exactly as LoadData's own format switch used to do
// inline, before ParseData needed the same switch for its one fixed format.
func decodeDataRoot(ext string, raw []byte) (map[string]json.RawMessage, error) {
	var root map[string]json.RawMessage

	switch ext {
	case JSON, JSONC:
		raw = []byte(text.StripJSONComments(string(raw)))

		if err := json.Unmarshal(raw, &root); err != nil {
			return nil, fmt.Errorf("failed to parse data file: %w", err)
		}
	case YAML, YML:
		var generic map[string]any

		if err := yaml.Unmarshal(raw, &generic); err != nil {
			return nil, fmt.Errorf("failed to parse data file: %w", err)
		}

		normalized, err := normalize(generic)
		if err != nil {
			return nil, fmt.Errorf("failed to parse data file: %w", err)
		}

		root = normalized
	case TOML, TML:
		var generic map[string]any

		if err := toml.Unmarshal(raw, &generic); err != nil {

View on GitHub (pinned to 0976794618)

Solutions

1. Run the file through a JSON linter/parser to locate the syntax error
2. Remove trailing commas and ensure keys/strings are double-quoted
3. Remove leftover git merge-conflict markers
4. Confirm the file extension matches the actual content format (rename to .yaml if it is YAML)

Example fix

// before (data.json)
{ "version": 1, }
// after
{ "version": 1 }

var probe any
if err := json.Unmarshal(raw, &probe); err != nil {
    return fmt.Errorf("invalid JSON in %s: %w", path, err)
}

func isValidJSON(raw []byte) bool { var v any; return json.Unmarshal(raw, &v) == nil }

data, err := config.LoadData(path)
if err != nil && strings.Contains(err.Error(), "failed to parse data file") {
    log.Fatalf("malformed JSON in %s: %v", path, errors.Unwrap(err))
}

When it happens

Trigger: Loading a .json/.jsonc data file containing a syntax error: trailing comma, unquoted key, stray comment not recognized, truncated file, or BOM/encoding issues.

Common situations: Hand-edited theme/data configs left malformed, a merge conflict marker (<<<<<<<) left in the file, copying YAML content into a .json file, or a tool writing partial output on crash.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• unclosed section:
• key-value delimiter not found:
• failed to parse theme %s
• failed to parse recorded theme %s: %w
• failed to parse env for theme %s: %w

AI-assisted analysis of JanDeDobbeleer/oh-my-posh@0976794618 (2026-08-31). Data as JSON: /api/errors/2a88ff0e865c1d91. Report an issue: GitHub.