prefix_except_default doesn't generate new routes

[wrkmartech]

Environment

• Operating System: Linux
• Node Version: v18.17.1
• Nuxt Version: 3.8.0
• CLI Version: 3.9.1
• Nitro Version: 2.7.1
• Package Manager: [email protected]
• Builder: -
• User Config: devtools, modules, i18n, css, app
• Runtime Modules: @nuxtjs/[email protected]
• Build Modules: -

Reproduction

https://stackblitz.com/edit/nuxt-starter-7insz7

Describe the bug

I have 2 initial routes:
pages/index.vue
pages/about.vue

and 3 locales: en, fr, es

Using the option "prefix_except_default" I expect to get a new array of routes, as described in doc:

[
  {
    path: '/',
    name: 'index___en'
  },
  {
    path: '/fr',
    name: 'index___fr'
  },
  {
    path: '/es',
    name: 'index___es'
  },
  {
    path: '/about',
    name: 'about___en'
  },
  {
    path: '/fr/about',
    name: 'about___fr'
  },
  {
    path: '/es/about',
    name: 'about___es'
  },
]

But new routes are not created

Additional context

No response

Logs

[Vue Router warn]: No match found for location with path "/fr"
[Vue Router warn]: No match found for location with path "/es"
[Vue Router warn]: No match found for location with path "/fr/about"
[Vue Router warn]: No match found for location with path "/es/about"
[Vue Router warn]: No match found for location with path "/fr"
[Vue Router warn]: No match found for location with path "/es"
[Vue Router warn]: No match found for location with path "/fr/about"
[Vue Router warn]: No match found for location with path "/es/about"

[BobbieGoede]

You need to set the locales option in the i18n config for this to work, I changed your reproduction to demonstrate [here].(https://stackblitz.com/edit/nuxt-starter-72yjba?file=i18n.config.ts,nuxt.config.ts)

I understand this is confusing as vueI18n detects the locales based on configured messages in i18n.config.ts separate from this module.