docker/cli · error

invalid type %T for map[string]string

Error message

invalid type %T for map[string]string

What it means

Error "invalid type %T for map[string]string" thrown in docker/cli.

Source

Thrown at cli/compose/loader/loader.go:692

	return obj, nil
}

func absPath(workingDir string, filePath string) string {
	if filepath.IsAbs(filePath) {
		return filePath
	}
	return filepath.Join(workingDir, filePath)
}

var transformMapStringString TransformerFunc = func(data any) (any, error) {
	switch value := data.(type) {
	case map[string]any:
		return toMapStringString(value, false), nil
	case map[string]string:
		return value, nil
	default:
		return data, fmt.Errorf("invalid type %T for map[string]string", value)
	}
}

var transformExternal TransformerFunc = func(data any) (any, error) {
	switch value := data.(type) {
	case bool:
		return map[string]any{"external": value}, nil
	case map[string]any:
		return map[string]any{"external": true, "name": value["name"]}, nil
	default:
		return data, fmt.Errorf("invalid type %T for external", value)
	}
}

var transformServicePort TransformerFunc = func(data any) (any, error) {
	switch entries := data.(type) {
	case []any:
		// We process the list instead of individual items here.

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at cli/compose/loader/loader.go:692 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/a44b03dc46d65b10.json. Report an issue: GitHub.