Turbopack Error: Failed to write app endpoint /[locale]/page

[mtr-devteam]

Turbopack version: 23c464985
Next.js version: 0.0.0

Error message:

Failed to write app endpoint /[locale]/page

Caused by:
- Next.js package not found

Debug info:
- Execution of Project::hmr_version_state failed
- Execution of Project::hmr_version failed
- Execution of VersionedContentMap::get failed
- Execution of VersionedContentMap::get_asset failed
- Execution of VersionedContentMap::compute_entry failed
- Execution of *emit_assets failed
- Execution of all_assets_from_entries_operation failed
- Execution of *all_assets_from_entries failed
- Execution of endpoint_output_assets_operation failed
- Execution of <AppEndpoint as Endpoint>::output failed
- Failed to write app endpoint /[locale]/page
- Execution of AppEndpoint::output failed
- Execution of AppEndpoint::app_page_entry failed
- Execution of *get_app_page_entry failed
- Execution of AppProject::rsc_module_context failed
- Execution of *ModuleAssetContext::new failed
- Execution of *AppProject::get_rsc_transitions failed
- Execution of AppProject::ecmascript_client_reference_transition failed
- Execution of *NextEcmascriptClientReferenceTransition::new failed
- Execution of AppProject::ssr_transition failed
- Execution of *FullContextTransition::new failed
- Execution of AppProject::ssr_module_context failed
- Execution of AppProject::shared_transition failed
- Execution of *FullContextTransition::new failed
- Execution of AppProject::shared_module_context failed
- Execution of *ModuleAssetContext::new failed
- Execution of get_server_resolve_options_context failed
- Execution of get_next_server_import_map failed
- Next.js package not found

[MahdiJDS]

The key part here is probably this line:

Next.js package not found

and the reported version:

Next.js version: 0.0.0

That usually points to a broken or unresolved next installation rather than an actual routing issue with /[locale]/page.

A few likely causes:

• corrupted node_modules
• workspace/monorepo resolution problems
• package manager hoisting issues
• mismatched next dependency versions
• lockfile corruption
• running Turbopack from a directory where next is not resolvable

I’d try the following first:

rm -rf node_modules .next
rm package-lock.json # or yarn.lock / pnpm-lock.yaml
npm install

Then verify:

npm ls next

to confirm that next is actually installed and resolvable.

If this is a monorepo, it may also be worth checking:

• whether next is installed in the correct workspace
• whether the app package has its own dependency entry
• and whether Turbopack is resolving from the expected root

The [locale]/page route itself is probably just the first endpoint that triggers module resolution, not necessarily the root cause.

Also worth testing:

next dev --no-turbo

If the app works without Turbopack, that would help narrow it down to Turbopack’s package resolution layer specifically.

Could you also share:

• package manager
• monorepo setup (if any)
• Node.js version
• and the relevant package.json dependencies?

That would make the issue easier to reproduce.