gorilla/mux · error

mux: route does not have a path

Error message

mux: route does not have a path

What it means

Returned by Route.GetPathRegexp (route.go:715-722) when introspecting the compiled path regexp of a route that has no path matcher. Note the slightly different wording ('does not have a path') versus GetPathTemplate/URLPath ('doesn't have a path') at the other call sites.

Source

Thrown at route.go:720

	if r.err != nil {
		return "", r.err
	}
	if r.regexp.path == nil {
		return "", errors.New("mux: route doesn't have a path")
	}
	return r.regexp.path.template, nil
}

// GetPathRegexp returns the expanded regular expression used to match route path.
// This is useful for building simple REST API documentation and for instrumentation
// against third-party services.
// An error will be returned if the route does not define a path.
func (r *Route) GetPathRegexp() (string, error) {
	if r.err != nil {
		return "", r.err
	}
	if r.regexp.path == nil {
		return "", errors.New("mux: route does not have a path")
	}
	return r.regexp.path.regexp.String(), nil
}

// GetQueriesRegexp returns the expanded regular expressions used to match the
// route queries.
// This is useful for building simple REST API documentation and for instrumentation
// against third-party services.
// An error will be returned if the route does not have queries.
func (r *Route) GetQueriesRegexp() ([]string, error) {
	if r.err != nil {
		return nil, r.err
	}
	if r.regexp.queries == nil {
		return nil, errors.New("mux: route doesn't have queries")
	}
	queries := make([]string, 0, len(r.regexp.queries))
	for _, query := range r.regexp.queries {

View on GitHub (pinned to db9d1d0073)

Solutions

1. Skip routes where GetPathRegexp errors.
2. Use GetPathTemplate for the human-readable template instead.
3. Filter to path-bearing routes first.

Example fix

// before
re, err := route.GetPathRegexp()
// errors on host-only routes

// after
re, err := route.GetPathRegexp()
if err != nil { re = "" }

re, err := route.GetPathRegexp()
if err != nil { re = "" }

func hasPathRe(rt *mux.Route) bool { _, err := rt.GetPathRegexp(); return err == nil }

re, err := rt.GetPathRegexp()
if err != nil { continue }

When it happens

Trigger: Calling GetPathRegexp() on a host-only or method-only route during metrics/docs generation.

Common situations: OpenAPI generators walking all routes; tracing libraries building route labels; refactor that removes Path.

Related errors

• mux: route doesn't have queries
• mux: route doesn't have methods
• mux: duplicated route variable %q
• mux: path must start with a slash, got %q
• mux: missing name or pattern in %q

AI-assisted analysis of gorilla/mux@db9d1d0073 (2026-08-04). Data as JSON: /data/errors/1b336915a24a1cd7.json. Report an issue: GitHub.