Stenope doesn't generate pages for localized routes

[Alexandre-Fernandez]

I have the following config :

config/services.yaml

parameters:
  app.supported_locales: "en|fr"

src/Controller/AppController.php

    #[Route("/{_locale<%app.supported_locales%>}", name: "index")]
    public function index(): Response
    { /* ... */ }

When I run php bin/console -e prod stenope:build ./static stenope doesn't generate any page for my route.

EDIT: I also tried replacing my custom parameter with enabled_locales, and it still doesn't work, is there a workaround ?