Issue with Next.js 15 Canary / withPayload / .mts

[Dan6erbond]

Description

I'm trying to use next-intl with Next.js 15 Canary and Payload 3 Beta, so I'm aware there might be bugs caused by being on the bleeding edge, but I'm running into an issue with the plugin loading the i18n.ts config file:

Error: Couldn't find next-intl config file. Please follow the instructions at https://next-intl-docs.vercel.app/docs/getting-started/app-router

I tried everything, from adding the following to my next.config.mts:

  experimental: {
    turbo: {
      resolveAlias: {
        "next-intl/config": "./src/i18n/config.ts",
      },
    },
  },

To moving the config.ts file to the default src/i18n.ts location, all to no avail.

Verifications

• I've verified that the problem I'm experiencing isn't covered in the docs.
• I've searched for similar, existing issues on GitHub and Stack Overflow.
• I've compared my app to a working example to look for differences.

Mandatory reproduction URL

https://gitea.ravianand.me/Dan6erbond/localbites-landing-page/src/branch/feature/next-intl

Reproduction description

Steps to reproduce:

1. Open reproduction
2. Launch app
3. See error

Expected behaviour

My website should open and I should be redirected to the homepage.

[amannn]

Hey! Can you try to isolate the issue further to pinpoint the exact place where the setup breaks?

I had a quick go at adding payload@beta, next@canary, react@rc and react-dom@rc to https://github.com/amannn/next-intl-bug-repro-app-router. I've then added withPayload and the setup still works.

Maybe you could try to diagnose the issue from that path, ideally noticing a single line change that causes the issue. Let me know if you can find something from this angle!

[Dan6erbond]

Well, it seems like I'm unable to reproduce the issue now in a new Next.js app. No idea what's different between the two because I started with the Next.js + next-intl setup, then added Payload and it still works. So I must be missing something in my setup in the repo I shared. I'll have to give it a closer look but for now I'll close this issue since it isn't related to next-intl. Thanks!