NextJs 15.3 shows warning after adding Sentry

[ChristianKohler]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which SDK are you using?

@sentry/nextjs

SDK Version

9.13

Framework Version

15.3

Link to Sentry event

No response

Reproduction Example/SDK Setup

No response

Steps to Reproduce

1. Install NextJs 15.3
2. Add Sentry using the wizard
3. Run npm run dev
4. See the following warning

Expected Result

No warning or a better way to understand that this warning comes in combination with Sentry. Since this is a NextJs warning I started to look into the turbopack configuration..

Actual Result

next dev --turbopack

   ▲ Next.js 15.3.0 (Turbopack)
   - Local:        http://localhost:3000
   - Network:      http://192.168.215.4:3000
   - Experiments (use with caution):
     · clientTraceMetadata

 ✓ Starting...
 ✓ Compiled instrumentation Node.js in 379ms
 ✓ Compiled instrumentation Edge in 134ms
 ✓ Ready in 1210ms
++ ⚠ Webpack is configured while Turbopack is not, which may cause problems.
++ ⚠ See instructions if you need to configure Turbopack:
  https://nextjs.org/docs/app/api-reference/next-config-js/turbo

[lforst]

This is known but you can safely ignore it. Next.js emits this warning because the Sentry SDK defines a webpack callback field and when you run with turbopack Next.js warns you in case it is critical for your app to run the webpack callback.

[lforst]

We can potentially fix this in the future when we only support Next.js versions that set the process.env.TURBOPACK env var when turbopack is used. Right now we need to unconditionally add the webpack callback because we cannot reliably detect turbopack due to old versions.

Maybe we can also add some flag to the SDK that will skip over adding this field.

[franzwilhelm]

+1 on this. Your solution sounds good @lforst