Every git fetch that dies mid-transfer (timeout, HTTP 429, dropped
line) strands a tmp_pack_* file in .git/objects/pack, and git never
cleans them. The banner's background update check is the main generator
on flaky lines — several aborted fetches a day — and the reporter's
install accumulated hundreds of files / 6.0 GB over 9 days until the
pack directory corrupted outright and every update check hung or
failed permanently.
clear_stale_tmp_packs() in gitlock.py sweeps tmp_pack_/tmp_idx_/
tmp_rev_/tmp_mtimes_ debris with the exact safety contract the lock
sweep already uses: only files past the 10-minute age floor, never
while any git process runs, never raises, real pack-*.pack/.idx files
untouchable by construction (prefix match). Wired into all three
fetch-adjacent sites: _cmd_update_check, the update apply path, and
the banner's passive check (generator = janitor).
Live E2E: 300 aged tmp_pack files (the reported scale-shape) swept
from a real repo; an in-flight fresh tmp and ancient real packs
survived; fsck clean and a real fetch round-trip succeeded after.
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