Link to the code that reproduces this issue

https://github.com/eliw00d/next-turbopack-configdir-repro

To Reproduce

1. From root, run rush update && rush build
2. Notice that app-with-error fails because of Import map: aliased to relative './components/Center' inside of [project]/rigs/web-rig/profiles/default/config/typescript/${configDir}/src

Current vs. Expected behavior

Current behavior

Building a Next.js app that extends another tsconfig.json does not parse ${configDir} and throws errors related to the import map.

Expected behavior

Building a Next.js app that extends another tsconfig.json parses ${configDir} and builds successfully.

Provide environment information

Operating System:
  Platform: linux
  Arch: x64
  Version: #1 SMP PREEMPT_DYNAMIC Thu Jun  5 18:30:46 UTC 2025
  Available memory (MB): 31923
  Available CPU cores: 16
Binaries:
  Node: 22.21.1
  npm: 10.9.4
  Yarn: N/A
  pnpm: N/A
Relevant Packages:
  next: 16.0.3 // Latest available version is detected (16.0.3).
  eslint-config-next: N/A
  react: 19.2.0
  react-dom: 19.2.0
  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), next build (local), next start (local)

Additional context

No response