halt_on_alert_query() ends with `grep -vE "$regex" | sort -u`. When
zero alerts are firing (the desired healthy state), grep matches
nothing and exits 1. Under `set -o pipefail`, the whole pipeline
returns 1; under `set -e`, the caller's `alerts=$(...)` assignment
fails and aborts the script in ~1s with no diagnostic output.
The chain effectively required at least one non-meta alert to be
firing to make any forward progress. Today (2026-05-19) the cluster
is fully clean post-MySQL recovery, the daily 12:00 UTC detection
spawned the preflight Job, and it died instantly — blocking the
1.34.7 → 1.34.8 patch chain.
Fix: wrap the grep in `{ ... || true; }` so a no-matches result
returns success. Preflight verified end-to-end after the fix — the
chain is now in flight (preflight ✓, master phase running).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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