Local Variables not being reported when hosting on Vercel

[cau777]

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

9.2.0

Framework Version

Next 15.2.0

Link to Sentry event

https://aerial-ops.sentry.io/issues/6340230618/events/4b04a367762c4da59f3ffc5d112adccb/?project=6255059

Reproduction Example/SDK Setup

GitHub repo: https://github.com/cau777/temp-sentry-nextjs-localvars

Steps to Reproduce

1. Create a NextJS project using create-next-app: npx create-next-app@latest temp-sentry-nextjs-localvars
2. Install Sentry with the wizard: npx @sentry/wizard@latest -i nextjs
3. Add includeLocalVariables: true to sentry.server.config.ts
4. Implement a test function under pages/api, for example:

const willThrow = () => {
  const hey = 12
  const value = 1
  const str = "some string"
  console.log(hey, value, str)
  throw new Error("Intentional error on Sentry reproduction 3")
}

export default function handler(_req, res) {
  try {
    willThrow()
  } catch (e) {
    captureException(e)
  }

  res.status(200).json({ name: "John Doe" });
}

5. Upload the project to a git repo and deploy to Vercel
6. Add SENTRY_AUTH_TOKEN to the env variables in Vercel

Expected Result

When navigating to the test API route on the deployed app, an error should be reported to Sentry, containing all 3 local variables from the willThrow function.

Actual Result

No local variables appear in the Sentry issue when the app is deployed on Vercel.

However, running the same code locally npm run dev reports local variables to Sentry as expected.

https://aerial-ops.sentry.io/issues/6340144143/events/d4f46bc86efa400db9fac4c8c8f5e8c1/?project=6255059

Vercel apps are deployed on AWS Lambda, maybe the debugger used by Sentry to extract local variables doesn't work in that environment?

[AbhiPrasad]

If you set debug: true in your Sentry.init call in sentry.server.config.ts what gets logged out? You'll also have to set disableLogger: false in your next.config.js

https://github.com/cau777/temp-sentry-nextjs-localvars/blob/62917bc2127414f1ff5035fb250a881c0155bbb8/next.config.ts#L37