De-flakes tests/hermes_cli/test_ssh_ownership_endpoint.py, which failed CI
twice on PR #95563 with teardown-time daemon-thread excepthook crashes — a
different test in the file each attempt, always green in isolation. Root
cause: three PROCESS-GLOBAL monkeypatches leaked into every other thread
sharing the per-file worker:
- monkeypatch.setattr(web_server.os, 'stat', ...) — web_server.os IS the os
module; any daemon thread from an earlier test that stat()ed during the
patch window got the fake 2-field stat and died in its excepthook, which
fired at interpreter teardown.
- monkeypatch.setattr('builtins.open', ...) — same class, worse blast radius.
- monkeypatch.setattr(web_server.sysconfig, 'get_paths', ...) — sysconfig is
process-global too.
Fixes, none of which weaken coverage:
- replaced-runtime test: a REAL tmp_path purelib whose recorded inode
deliberately mismatches (st_ino + 1) — real os.stat, same code path.
- readonly-purelib test: chmod 0o555 on the real directory instead of an
open() interceptor — exercises the genuine OSError branch (root-skipped,
where mode bits aren't enforced).
- sysconfig patches swapped for a SimpleNamespace on the web_server module
attribute — module-scoped, invisible to other threads.
Verified: 14 consecutive full-file runs green; sabotaging
_ssh_runtime_intact to always-True still fails 2 tests (coverage intact).
Follow-up on the cherry-picked #82644: the (st_dev, st_ino) snapshot of
site-packages does not survive contact with ext4 — a recreated directory
routinely REUSES the freed inode, so the exact reported repro
(rm -rf venv && uv venv) passed the intact check undetected. Proven live
during salvage: the E2E's replaced venv came back with the identical
inode and runtimeIntact stayed true.
Primary identity is now a marker file written into site-packages when
the SSH owner nonce activates: it deterministically dies with the old
tree on ANY replacement (same or different Python version) and survives
in-place pip/uv installs (no false stales). The stat snapshot remains as
the fallback for read-only site-packages, where it still catches
cross-device moves and version-bump path changes. Client classifier
semantics unchanged: only an explicit runtimeIntact:false rejects, so
older remotes stay compatible.
Three new tests: recreated-venv-with-reused-inode (the live-proven
case), in-place-install stays intact, read-only fallback arms the stat
tier.
Accept descriptor-safe one-shot token files and exact owner nonces, expose an authenticated ownership proof endpoint, and preserve the process-local contract across parser and server startup paths.
Teknium