Description

When running the same Gradle task twice in a row on Windows, the 2nd run fails with a file-lock error on classes.jar.

This is reproducible only on Windows and only with KSP2 enabled (ksp.useKSP2=true).
With KSP1 (ksp.useKSP2=false) the issue does not reproduce.

Minimal reproducer repo:
https://github.com/ruxbit/ksp2reproducer

Environment

• JDK: JetBrains Runtime 21.0.8
• Gradle: 8.13
• Android Gradle Plugin: 8.10.0
• Kotlin Gradle Plugin: 2.2.21
• KSP Gradle Plugin: 2.2.21-2.0.5

Steps to reproduce

1. Clone the reproducer:
   https://github.com/ruxbit/ksp2reproducer

2. Ensure KSP2 is enabled:

   • ksp.useKSP2=true (via gradle.properties)

3. Run this command (1st run succeeds):
   ./gradlew :lib:common:media:assembleDebug --rerun-tasks

4. Run the same command again (2nd run fails):
   ./gradlew :lib:common:media:assembleDebug --rerun-tasks

Actual result

2nd run fails with:

Execution failed for task ':lib:common:collections:bundleLibCompileToJarDebug'.
java.nio.file.FileSystemException: D:\Wildberries\ksp2reproducer\lib\common\collections\build\intermediates\compile_library_classes_jar\debug\bundleLibCompileToJarDebug\classes.jar: The process cannot access the file because it is being used by another process

Expected result

The 2nd run should also succeed (no stale file handle / no locked classes.jar).

Additional notes / observations

• Reproduces only on Windows (Linux/macOS do not reproduce).
• Reproduces only with KSP2:
  • ksp.useKSP2=true -> fails on 2nd run
  • ksp.useKSP2=false -> OK (both runs succeed)
• If I remove ksp(libs.androidx.room.compiler) from module :lib:common:media, the issue disappears.
• If I keep KSP enabled but use any other KSP processor instead of Room, the issue still reproduces.
• Project structure is intentionally minimal:
  • :lib:common:collections contains only a single Kotlin class A
  • :lib:common:media contains only B(val a: A), depends on collections, applies KSP, and adds a KSP processor dependency