[Turbopack] React DevTools shows "production build" warning in development mode due to extra production renderer

[sapn1s]

Link to the code that reproduces this issue

https://github.com/sapn1s/create-next-app-16.1.6?target=https://github.com

To Reproduce

1. Create a new Next.js 16 app: npx create-next-app@16.1.6 test-app --yes
2. Start dev server: npm run dev
3. Open http://localhost:3000 in browser with React DevTools extension installed
4. Click the React DevTools extension icon - observe "This page is using the production build of React" message
5. Open browser console and run:

   window.__REACT_DEVTOOLS_GLOBAL_HOOK__?.renderers

6. Observe 3 renderers with mixed bundleType values

Current vs. Expected behavior

Current behavior

React DevTools displays "This page is using the production build of React" when running next dev.

Console shows 3 React renderers:

Map(3) {
  1 => { bundleType: 1, rendererPackageName: "react-dom", ... }           // development
  2 => { bundleType: 1, rendererPackageName: "react-server-dom-turbopack", ... }  // development
  3 => { bundleType: 0, rendererPackageName: "react-dom", ... }           // PRODUCTION
}

bundleType: 0 = production, bundleType: 1 = development

DevTools sees the production renderer (#3) and warns the user, even though client components use the development renderer (#1).

Expected behavior

In development mode (next dev), only development React renderers should be present. React DevTools should show "This page is using the development build of React" or no warning.

Provide environment information

Operating System:
  Platform: win32
  Arch: x64
  Version: Windows 11 Pro
  Available memory (MB): 31832
  Available CPU cores: 16
Binaries:
  Node: 24.12.0
  npm: 11.6.2
  Yarn: N/A
  pnpm: N/A
Relevant Packages:
  next: 16.1.6 // Latest available version is detected (16.1.6).
  eslint-config-next: N/A
  react: 19.2.3
  react-dom: 19.2.3
  typescript: 5.9.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Turbopack

Which stage(s) are affected? (Select all that apply)

next dev (local)

Additional context

Impact: Cosmetic only. React Profiler and "Record why each component rendered" features work correctly. The warning is misleading but does not affect functionality.

Using latest official extension React Developer Tools - Version 7.0.1 (10/20/2025)

[jonas-is-coding]

This issue suggests that the production React renderer is incorrectly loaded in development mode within Turbopack. Ensure that your environment variable is explicitly set to . It might also help to clear the cache and and reinstall to ensure no stale builds or caching issues are the cause. If custom Turbopack configurations are being used, it's crucial to verify that and are correctly resolved to their development versions.

[sapn1s]

This issue suggests that the production React renderer is incorrectly loaded in development mode within Turbopack. Ensure that your environment variable is explicitly set to . It might also help to clear the cache and and reinstall to ensure no stale builds or caching issues are the cause. If custom Turbopack configurations are being used, it's crucial to verify that and are correctly resolved to their development versions.

Any chance you could stop going on issues and pasting AI slop?