A git push is a two-request exchange: GET info/refs?service=git-receive-pack
(ref advertisement) then POST git-receive-pack (the pack). The git-HTTP host
classified BOTH as serviceKind 'write' and routed both through
ingestExternalPush, which takes the per-space lock and runs a FULL Docmost
reconcile cycle. So the read-only info/refs advertisement held the lock while a
cycle ran, and the client's immediately-following POST git-receive-pack collided
with that still-running cycle and got 503 — deterministically, every push (and
Obsidian Git's "scan" failed for the same reason, since it probes push
capability via the same receive-pack info/refs).
Fix: only the actual pack-receiving write (POST git-receive-pack) runs under the
lock + cycle. Everything else streams the http-backend directly with no lock and
no cycle — a fetch/clone (read) AND the write-AUTHORIZED but read-only
info/refs?service=git-receive-pack advertisement. Authz is unchanged (the gate
still requires write permission for receive-pack refs); only the side effect of
running a cycle on a read-only request is removed.
Verified end-to-end on a live stand: clone, then `git push` of a new file lands
the page in Docmost (was 503 on every push before). Regression test added.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
452a752264