The check has been blocking the staging→main auto-promote PR (#2361)
since 2026-04-30T07:17Z with:
fatal: origin/main...<head>: no merge base
Root cause: the workflow does `git fetch origin <base> --depth=1`
which overwrites checkout@v4's full-history clone with a shallow
tip — destroying the ancestry the subsequent
`git diff origin/main...HEAD` (three-dot, merge-base form) needs.
This deadlocks every staging→main promote PR until manually fixed.
The auto-promote runs were succeeding at the gate-check phase but
the subsequent PR-merge step waited 30 min for the failing check
and timed out, skipping the publish + redeploy dispatch tail.
Fleet recovery for any production-only fix went through staging
fine but never reached main.
Fix: drop --depth=1 so the explicit fetch preserves full history.
The leading comment is updated to call out this trap so a future
maintainer doesn't re-add the flag thinking it's a perf win.
No test added: this is a workflow-config one-liner that the
existing PR check itself exercises end-to-end (the real signal is
PR #2361 going green after this lands).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
a9391c5900