test_staged_root_sourced_doc_with_stale_mirror_fails errored in the
"Script smoke tests & backend build" job on PR #1857 (run 33609703555)
with OSError [Errno 39] Directory not empty: '.git' raised from
TemporaryDirectory cleanup. The test body passed; a background git
process spawned by init/add/commit (auto-gc, fsmonitor, or maintenance)
was still writing under .git when shutil.rmtree ran. The suite passes on
main most of the time and locally, so this is a race, not a logic bug.
Disable gc.auto, core.fsmonitor and maintenance.auto for the throwaway
repos, and point GIT_CONFIG_GLOBAL/GIT_CONFIG_SYSTEM at os.devnull so a
runner's host config cannot re-enable them. Construct both temp
directories with ignore_cleanup_errors=True as a belt-and-braces fallback
so a straggler can never fail a test whose assertions already passed.
Docs under frontend-modern/public/docs are byte-for-byte copies of repo
docs, but the only guard was a CI vitest the git hooks never run. On
2026-09-01 two commits (f4886c2dfb, f313882a7b) each edited a mirrored
doc without its copy, passed the hooks, and broke main's Frontend job.
Add scripts/check_docs_mirror.py with an index-blob --staged mode wired
into the pre-commit hook: a commit that stages either side of an
out-of-sync pair (or an orphan shipped copy) fails with the exact sync
command, while pre-existing drift from other commits only warns. The
worktree mode runs as a named step in the public-docs workflow, with
unit tests in scripts/tests picked up by the existing runner. The
docsLinks vitest stays as the CI backstop.
Build-time generation of public/docs was considered and rejected: the
shipped set is a curated subset (61 of 421 docs), so generation still
needs a hand-maintained manifest while adding build, dev-server, and
test-order coupling.
rcourtman