GitHub Actions Cache From Another Workflow Run Not Restored
By Daniel Zoghalchali·Latchkey
A cache saved in one run is not restored in another because cache access is scoped by branch. A run can read caches from its own branch and the base/default branch - but not from unrelated feature branches.
What this error means
A feature-branch run misses a cache that a different feature branch populated, even with the same key, because cache scoping does not share across sibling branches.
Actions log
# branch feature/a saved key deps-abc123
# branch feature/b run misses it -> rebuilds
Cache not found for input keys: deps-abc123
Common causes
Cache scope is per branch
Caches are scoped to the branch that created them, plus read access to the base and default branch. A different feature branch cannot read another feature branch’s cache.
Expecting a global cache
Assuming any run can read any cache by key ignores the branch-scoping rule, so cross-branch reuse silently misses.
How to fix it
Seed the cache on the default branch
Run the cache-producing workflow on the default branch so feature branches inherit it via base-branch read access.
.github/workflows/warm-cache.yml
# a scheduled/push job on the default branch warms the cacheon:push:branches:[main]# feature branches then restore it via base-branch scope
Use restore-keys for partial hits
Add restore-keys prefixes so a near-match from the base branch still helps.
Warm shared caches on the default branch, not on feature branches.
For cross-run artifacts (not deps), use artifacts with run-id download instead.
How to prevent it
Warm shared caches on the default branch so all branches can read them.
Use restore-keys prefixes to survive key changes and branch scoping.
Do not expect sibling feature branches to share each other’s caches.
Frequently asked questions
What causes "Cache across runs"?
Caches are scoped to the branch that created them, plus read access to the base and default branch. A different feature branch cannot read another feature branch’s cache.
How do I fix Cache across runs?
Run the cache-producing workflow on the default branch so feature branches inherit it via base-branch read access.
Can Latchkey fix this automatically?
Yes. Latchkey runs your GitHub Actions on managed runners that detect this failure, apply the fix, and retry the job automatically - self-healing is on by default.
