Turbopack Error: Failed to write app endpoint /page

[rajanand73073]

Turbopack version: db56d775
Next.js version: 0.0.0

Error message:

Failed to write app endpoint /page

Caused by:
- [project]/src/app/globals.css [app-client] (css)
- creating new process
- reading packet length
- unexpected end of file

Debug info:
- Execution of TaskId { id: 2147483653 } transient failed
- Execution of get_written_endpoint_with_issues_operation failed
- Execution of endpoint_write_to_disk failed
- Execution of <AppEndpoint as Endpoint>::output failed
- Failed to write app endpoint /page
- Execution of AppEndpoint::output failed
- Execution of AppProject::app_module_graphs failed
- Execution of *<AppEndpoint as Endpoint>::additional_entries failed
- Execution of *ModuleGraph::from_graphs failed
- Execution of SingleModuleGraph::new_with_entries_visited_intern failed
- [project]/src/app/globals.css [app-client] (css)
- Execution of primary_chunkable_referenced_modules failed
- Execution of <CssModuleAsset as Module>::references failed
- Execution of parse_css failed
- Execution of <PostCssTransformedAsset as Asset>::content failed
- Execution of PostCssTransformedAsset::process failed
- creating new process
- reading packet length
- unexpected end of file

[TheusHen]

The error you’re seeing:

Failed to write app endpoint /page
Caused by:
- [project]/src/app/globals.css [app-client] (css)
- creating new process
- reading packet length
- unexpected end of file

This usually indicates that Turbopack crashed while processing your CSS pipeline (most likely inside globals.css or a PostCSS transformation). Because Turbopack is still experimental, these kinds of issues can show up when it tries to compile assets.

---

Things you can try

1. Check globals.css for syntax errors
   Even a small typo (like a missing } or invalid CSS property) can cause the parser to fail. Try running:

   npx postcss src/app/globals.css

   to verify if it parses cleanly.

2. Remove experimental config temporarily
   If you have custom PostCSS plugins or experimental Next.js config in next.config.js, try disabling them to see if the error goes away:

   const nextConfig = {
     experimental: {
       turbo: false, // disable turbopack fallback
     },
   };
   module.exports = nextConfig;

3. Clear the .next cache
   Sometimes corrupted build artifacts trigger this:

   rm -rf .next
   npm run dev

4. Update Next.js / Turbopack
   Since you’re on Next.js version: 0.0.0 (probably nightly or canary build), make sure you’re on the latest commit:

   npm install next@canary

5. Try without globals.css
   Rename globals.css temporarily and see if the error disappears. If it does, the problem is inside that file or one of its PostCSS imports.

---

Why this happens

• Turbopack is still not production-ready. Errors like “unexpected end of file” mean the bundler crashed while parsing assets (CSS in this case).
• The build system tries to spawn a process to handle the CSS, but the process ends before completing → leading to the EOF error.

---

Suggested Fix

• Start by validating your CSS file.

• If the CSS is fine, disable extra PostCSS plugins and rebuild.

• If nothing works, run with Webpack temporarily until Turbopack stabilizes:

  npm run dev -- --webpack

---

👉 In short: validate your CSS, clear cache, update Next.js, and disable experimental config if needed. If the issue persists, you may need to stick to Webpack for now.

[tim-eastwood]

This doesn't fix it - v4 doesn't include postcss by default, see fix here: #83856