The 300ms in-process SIGALRM budget in hook-augment self-terminated
with a silent _exit(0) on real cold starts (SQLite/mmap open under
load), so PreToolUse augmentation never appeared in real sessions
(reporter: 0/24 observed) while warm manual invocations worked - and a
fired deadline was indistinguishable from a legitimate no-match run.
Default budget is now 2000ms (the settings.json hook timeout stays the
outer backstop), overridable via CBM_HOOK_DEADLINE_MS (clamped
50..10000). When the deadline fires, the handler write()s a
pre-formatted breadcrumb (deadline, pid, the env knob to raise) to
~/.cache/codebase-memory-mcp/logs/hook-augment-timeouts.log before
exiting - fd and message are prepared at arm time so the handler stays
async-signal-safe; CBM_HOOK_TIMEOUT_LOG overrides the path for tests.
Windows keeps relying on the settings.json timeout (unchanged no-op).
Deterministic reproduction: stdin is a pipe whose writer never sends,
so the read blocks past a 60ms deadline - the timer must fire, exit 0
(fail-open), and leave the breadcrumb. RED before (no breadcrumb),
GREEN after.
Closes#858
Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>
Martin Vogel
39ffb97ceb