The #86687 self-lock preflight fired on every Windows `hermes update`:
bitwarden.py's module-level cryptography import (fixed in #86782 /
#86826-class change) meant cryptography._rust was ALWAYS mapped by the
time the preflight ran, so the update exited 2 before even fetching and
looped forever — including the Desktop in-app update (#86780).
Two structural fixes so the guard can never re-brick the flow it protects:
1. Version-gated detection: _detect_self_loaded_native_modules() now
consults _dependency_sync_would_rewrite(dist) — installed version vs
the on-disk pyproject pins (base deps + all extras, env markers
honored). A loaded module whose distribution the sync will not touch
is no lock risk and is not reported. Unknown → fail closed.
2. Relocated deferral: the check no longer runs pre-fetch. It runs via
_abort_dependency_sync_if_self_locked() immediately before each venv
rewrite (git-path dep sync, ZIP-path dep sync, current-checkout venv
repair) — AFTER the code swap. A deferral now leaves the user on NEW
code with only the dependency install pending (completed by the next
launch's marker recovery), instead of stranding them on the old
checkout in an exit-2 loop.
PyYAML's _yaml extension (loaded by every CLI process) joins the
registry — with version gating it is now safe to list.
Tests: version-gate unit coverage (no-change skip, stale pin, missing
dist, extras, markers, fail-closed None), deferral wiring (marker +
gateway resume + exit 2), placement guards (no detector call pre-fetch;
guard present at git/ZIP sync), and subprocess-verified import hygiene
(import hermes_cli.main and the update --check dispatch never load
cryptography._rust).
Follow-up to #86687 (Halldrix's #83590 salvage — the preflight's intent
stands as defence-in-depth; this makes it fire only when true).
Fixes#86735Fixes#86780Fixes#86781
Two gaps left every Windows git-checkout install unable to recover from
the exact failure state #83569 reports:
1. Self-lock detection. _detect_venv_python_processes() always excludes
the calling process by design — a CLI hermes update IS the venv python.
An updater that had already imported a native venv extension (the
canonical one being cryptography.hazmat.bindings._rust, mapped while
hermes_cli.main resolved external secret sources) passed every
preflight and then died mid-sync with os error 5 when uv tried to
rewrite the mapped .pyd, stranding the venv half-updated. A new
preflight now refuses the sync before touching the checkout, writes
the update-incomplete marker so the next fresh launch completes the
install, and exits 2. Verified on a live Windows 11 host: after
importing hermes_cli.main, tasklist /m _rust.pyd shows the .pyd mapped
in the caller, and a peer process cannot open it read-write
(Permission denied) — while a rename succeeds, matching how uv/pip
actually fail (truncate+write, not rename).
2. Early-recovery install path. _early_recovery._run_repair_install used
sys.executable -m pip unconditionally. Windows git checkouts install
on a uv-managed base interpreter (python-build-standalone), whose
EXTERNALLY-MANAGED marker makes plain pip abort with
externally-managed-environment — the repair no-oped and the venv
stayed broken. The repair now detects the PEP 668 marker, prefers
uv pip install with VIRTUAL_ENV pointed at the project venv, and
falls back to pip --break-system-packages when no uv binary exists.
Both fixes ship with subprocess/unit regressions (sabotage-verified):
the new tests fail on pre-fix code and pass with it. Complements #77517,
which keeps the updater from importing cryptography in the first place;
this PR is the defence-in-depth when any future path loads it anyway.
Fixes#83569
Teknium