A process running mismatched module versions — conversation_compression.py
re-imported with the post-#34351 lock code while a long-lived
hermes_state.SessionDB stays bound to the pre-#34351 class in memory — has
the try_acquire_compression_lock call site but not the method. The
AttributeError it raises is NOT a sqlite3.Error, so the method's own
fail-open guard never runs; the exception escapes to the outer agent loop,
which prints the error and retries. Compression never succeeds, the token
count never drops, and the loop re-triggers compaction forever (the
'API call #47/#48/#49 ... has no attribute try_acquire_compression_lock'
spin a user hit after an update).
Wrap the lock acquire so any unexpected exception fails OPEN: skip locking
and proceed with compression. Skipping the lock risks a rare
concurrent-compression session fork; an infinite no-progress loop that never
compresses at all is strictly worse. The remediation hint in the log points
at the real fix (restart / hermes update to resync the stale module).
Also guards get_compression_lock_holder against the same skew.
Adds a regression test simulating the version skew (real SessionDB wrapped
so only the lock methods raise AttributeError) — asserts _compress_context
proceeds and rotates instead of raising.
db2ce9e7d2