Minified function names in turbopack prod builds for server-side code

[chargome]

Link to the code that reproduces this issue

https://github.com/chargome/repro.turbopack-prod-server-sourcemaps

To Reproduce

Reproduction steps are in the readme file of the repro.

Current vs. Expected behavior

When building a Next.js app using next build, the names field in the source map files for server-side code is always empty which results in mappings not being able to reference an index from minified filename to original filename. This is only the case for server-side sourcemaps, not for client-side.

If this information is omitted due to performance reasons I would expect the next config to provide some option to opt-out of this behaviour.

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.5.0: Tue Apr 22 19:54:49 PDT 2025; root:xnu-11417.121.6~2/RELEASE_ARM64_T6000
  Available memory (MB): 32768
  Available CPU cores: 10
Binaries:
  Node: 20.14.0
  npm: 10.7.0
  Yarn: 1.22.22
  pnpm: 10.19.0
Relevant Packages:
  next: 16.1.1 // Latest available version is detected (16.1.1).
  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 build (local), Vercel (Deployed), Other (Deployed)

Additional context

No response

[lukesandberg]

@chargome is populating names sufficient to close this?

fixing next.js to leverage names when printing errors is possible but a substantial complexity increase (as i am sure you know since sentry does support this)

[chargome]

@lukesandberg For our sourcemaps resolution this should be sufficient!