Reproduction

Repository: https://github.com/hardfist/rspack-persistent-cache-missing-build-deps-recovery-repro

This is a JavaScript repro using the public compiler API and the published @rspack/core@2.1.4 package:

pnpm install
pnpm repro

The repro uses a loader that reads an external flag.txt file. That file is explicitly listed in cache.buildDependencies, so changing it should invalidate the persistent cache.

Steps:

1. Build with flag.txt = A.
2. Remove all records from the snapshot_build scope and recompute its pack integrity hash.
3. Change flag.txt to B and start a fresh process against the cache.
4. Compare with a cold build.

Observed on @rspack/core@2.1.4:

recovered exit: 0
recovered output contains A: true
recovered output contains B: false
cold build has errors: false
cold output contains B: true

BUG REPRODUCED: missing build-dependency recovery keeps stale output.

The recovered build succeeds but silently emits the old result even though the explicitly configured build dependency changed.

Expected behavior

An absent/incomplete snapshot_build scope should invalidate the cache or conservatively rerun build-dependency validation. A changed file listed in cache.buildDependencies must not be ignored during persistent-cache recovery.

Environment

• @rspack/core@2.1.4
• Node.js 24
• macOS arm64