Link to the code that reproduces this issue

https://github.com/paschun/next-app-icon-repro

To Reproduce

1. Place icons in app dir, like docs say. Two of them should have the same name. Like icon.png + icon.svg.
2. next build
3. Error:

> Build error occurred
Error [TurbopackInternalError]: Dependency tracking is disabled so invalidation is not allowed at /Users/geist/dev/actions-runner/_work/next.js/next.js/turbopack/crates/turbo-tasks-backend/src/backend/mod.rs:1514:13

4. Remove either icon.png or icon.svg, or place in public/
5. next build
6. Build succeeds

Current vs. Expected behavior

I expcted the build to succeed even with icon.png and icon.svg in the app/ directory.

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 25.0.0: Wed Sep 17 21:35:32 PDT 2025; root:xnu-12377.1.9~141/RELEASE_ARM64_T6020
  Available memory (MB): 16384
  Available CPU cores: 12
Binaries:
  Node: 24.10.0
  npm: 11.6.0
  Yarn: N/A
  pnpm: 10.20.0
Relevant Packages:
  next: 16.0.1 // Latest available version is detected (16.0.1).
  eslint-config-next: N/A
  react: 19.2.0
  react-dom: 19.2.0
  typescript: 5.9.3
Next.js Config:
  output: standalone

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

Output

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

next build (local)

Additional context

Safari <26 needs icon.png, doesn't support icon.svg. https://caniuse.com/link-icon-svg

Relevant discussions:
#85232
#84585