hermes-agent/.github/actions/save-pm-cache

Bundle dependency caches

setup-pm restores uv's real cache, not the installed virtual environment. Its fallback keys retain the native target, OS version, Python version, and pruning mode. A metadata or dependency change can reuse compatible wheels; uv still resolves and installs from the frozen project lock.

Bundle jobs set save-python-cache: false and call save-pm-cache after their build step with the python-path, uv-cache-path, and python-cache-key outputs. Both the caller and this composite use !cancelled() so a failed build does not suppress the save. Cancellation is excluded to avoid racing a dying uv process. A runner crash or job timeout can still prevent the save.

Snapshots use a run ID, attempt, and producer job suffix because Actions caches are immutable. Sibling bundle workflows in one caller run must not race to save different contents under the same key. Restore tries the current dependency set's rolling snapshots first, then the compatible v2 prefix. There is no fallback to older cache formats. This lets a retry add wheels to a snapshot saved by a partially failed build. The ordinary automatic cache path and its exact-hit smoke tests remain available.

Smoke namespaces precede the native/dependency identity, outside production's restore prefix. PM Toolchain cleanup removes its run-scoped snapshots.

Before saving, python -m pm.build_env --prune-cache --cache PATH removes dangling entries. It does not use --ci: that option discards downloaded wheels, while bundles copy the full cache for offline dependency installation. Pruning happens after payload staging and packaging, and it does not change the staged payload.

This is not a lockfile-aware or size-bounded cache. Old, still-referenced package versions can remain inside a snapshot and be copied forward. GitHub evicts whole cache snapshots under its retention and repository quota policies; that does not remove old versions inside the newest snapshot. A future size policy must account for the offline payload too, rather than deleting uv internals or promising that prune keeps only the current lock.