Impossible to use next-intl with Turbopack dev flag

[joshverd]

Description

It seems like using the --turbo flag with the Nextjs dev server is currently not possible. There appears to be a mismatch with how the config file is resolved at different points in the dev server operation.

If I start the Next dev server without --turbo and the following config, everything works great:

/**
 * This works for Webpack
 * 
 * But NOT for starting the Turbo dev server
 */
const withNextIntl = createNextIntlPlugin(
  'i18n/request.ts',
);

But this does NOT work with turbo:

Error: [next-intl] Could not find i18n config at i18n/request.ts, please provide a valid path.

Second, I tried setting up another config file path, starting from src/ this time:

/**
 * This works for STARTING the Turbo dev server
 * 
 * But this will throw an error in layout.tsx when loading localhost:3000
 */
const withNextIntl = createNextIntlPlugin(
  'src/i18n/request.ts',
);

The dev server starts just fine, but once I load the project in the browser it throws an error in layout.tsx:

 ✓ Compiled / in 1295ms
 ⨯ Error: Couldn't find next-intl config file. Please follow the instructions at https://next-intl.dev/docs/getting-started/app-router
    at RootLayout (src/app/layout.tsx:20:31)
  18 |   children: React.ReactNode
  19 | }) {
> 20 |   const locale = await getLocale();

This could be related to how I structure my projects. All Nextjs frontend code is contained within the src/ dir. Check package.json in the repro repository to see the scripts I am using to start Next.

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://github.com/joshverd/next-intl-bug-repro

Reproduction description

1. Clone repro repository
2. Run npm i
3. Open src/next.config.ts
4. Run npm run dev-turbo

Expected behaviour

I expect the dev server to 1) start properly and 2) render my layout.tsx and page.tsx files correctly.

[amannn]

It seems like there are the following issues here:

1. The path to i18n/request.ts needs to be relative (e.g. ./src/i18n/request.ts) or simply removed (since you use the default)
2. The [directory] option for next dev doesn't work properly, you can resolve this by moving next.config.ts one folder up and calling next dev --turbo instead

I think what next-intl could do better is:

1. Consistently handle relative paths (currently your input passes the validation but fails at runtime)
2. Maybe support the [directory] option (I didn't even know this was supported, it's the first time I saw it)

But with the steps mentioned above you should be able to work around the issue for now.

[joshverd]

Gotcha, that makes sense. I really appreciate the help here!

I tried digging through the next-intl code and debugging but I think Turbopack strips out any logging from node modules, which made it extremely difficult.

[github-actions]

This issue has been automatically closed because there was no recent activity and it was marked as unconfirmed. Note that issues are regularly checked and if they remain in unconfirmed state, they might miss information required to be actionable or are potentially out-of-scope. If you'd like to discuss this topic further, feel free to open a discussion instead.

[kevinrss01]

Any solution found for this issue???

[joshverd]

Yeah, follow the instructions outlined by @amannn above and it works just fine.