tree 98d83b35b896631833083b50f398a4e394318adf
parent f90d657b000700e23dfc9e1b5ea9bd3a58774bc5
author Googler <chiwang@google.com> 1725891799 -0700
committer Copybara-Service <copybara-worker@google.com> 1725891870 -0700

Make HTTP cache works with cache eviction.

Previously, it's possible for an HTTP cache to delete CAS entries referenced by AC without deleting the AC itself because HTTP cache doesn't understand the relationship between AC and CAS. This could result in permanent build errors because Bazel always trust the AC from remote cache assuming all referenced CAS entries exist.

Now, we record the digest of lost blobs before build rewinding, so that during the next build, we can ignore the stale AC and continue with execution.

Fixes #18696.

RELNOTES: Added support for using a remote cache that evicts blobs and doesn't have AC integrity check (e.g. HTTP cache).
PiperOrigin-RevId: 672536163
Change-Id: Ic1271431d28333f6d86e5963542d15a133075157