Two tests fail deterministically on main depending only on which SQLite the
test interpreter links — nothing about the code under test. Both are green in
isolation and red in the suite / on an older library, the worst diagnostic
shape.
Root cause A — WAL is not always WAL. Hermes refuses journal_mode=WAL on
SQLite builds carrying the upstream WAL-reset corruption bug (3.7.0–3.51.2,
excluding backports 3.50.7 / 3.44.6) and falls back to DELETE. On such a
build NO -wal sidecar is ever created, so
test_wal_checkpoint_truncates_wal_file asserts on a file that cannot exist.
Invisible locally when the repo .venv and the Hermes managed runtime link
different versions (observed: .venv 3.50.4 → DELETE, runtime 3.53.1 → WAL),
so the same test passes for one interpreter and fails for the other.
- tests/conftest.py: add a `requires_wal` marker plus a
pytest_collection_modifyitems hook that skips such tests when the linked
library will fall back to DELETE. The skip reason names the actual
version so it is diagnosable rather than mysterious.
- pyproject.toml: register the marker.
- test_kanban_db_repair.py: mark the -wal-sidecar test.
Root cause B — process-global warn-once dedup. The WAL-fallback warning is
emitted at most once per (process, db_label). Any earlier test in
test_kanban_db.py that opens a kanban.db consumes that one-shot, so
test_connect_falls_back_to_delete_on_locking_protocol sees zero warnings and
fails — but only as part of the file, never alone.
- test_kanban_db.py: clear both dedup sets in the test that asserts on the
warning, with a comment explaining the isolation trap.
The gate deliberately does NOT import hermes_state. That module computes
DEFAULT_DB_PATH from get_hermes_home() at import time, so importing it during
collection — before the per-test _isolate_hermes_home fixture redirects
HERMES_HOME — permanently caches the developer's REAL ~/.hermes/state.db for
the whole session. The first version of this change did exactly that and made
tests read a live 31,881-session production database (test_console_engine
asserted "Total sessions: 2" and got 31881). The version predicate is
duplicated instead, and tests/test_conftest_wal_gate.py pins the two
implementations in agreement across every documented upstream boundary plus
guards against the import coming back.
Verified: on SQLite 3.50.4 the sidecar test SKIPS naming the version; on
3.53.1 it RUNS and passes, so coverage is not lost where WAL works. Clean
main fails exactly these 2 tests under
`scripts/run_tests.sh tests/hermes_cli/ tests/test_hermes_state.py`
(9926 passed, 2 failed); with this change the same scope is green.
Tests: 726 passed across the two kanban files, test_hermes_state.py, and the
new gate tests.