/sitemap/[slug] and sitemap.ts conflicts in Nextjs15 (app router)

[timkinsman]

Summary

Hey, when migrating from next14 to next15 (both app router). It seems that having a page for app/sitemap/[slug]/page.tsx (a HTML sitemap) and app/sitemap.ts (a XML sitemap) causes errors. Is this intentional? I'm aware that a related change was posted in the blog.

• [Breaking] Remove .xml extension for dynamic sitemap routes and align sitemap URLs between development and production (PR)

However, I can't seem to wrap my head around it, is the above scenario just not achievable now?

Additional information

Error: You cannot use different slug names for the same dynamic path ('slug' !== '__metadata_id__').
    at Array.forEach (<anonymous>)
 ⨯ unhandledRejection: Error: You cannot use different slug names for the same dynamic path ('slug' !== '__metadata_id__').
    at Array.forEach (<anonymous>)
 ⨯ unhandledRejection:  Error: You cannot use different slug names for the same dynamic path ('slug' !== '__metadata_id__').
    at Array.forEach (<anonymous>)

Example

/~https://github.com/timkinsman/nextjs15-bugrepro-sitemap-conflict

[smoglica]

I'm experiencing the same issue. I'm using Next.js 15.1.6. I had no problems when using next dev, if I use turbopack with next dev --turbo I get: