hermes-agent/tests/tools/test_env_probe.py
Teknium b9dba7eff5
fix(env-probe): stuck Windows probe can no longer deadlock system-prompt builds (#67999)
An orphaned pip descendant holding the probe's inherited stdout/stderr
pipe handles wedged subprocess.run's post-timeout communicate() (which
joins the pipe reader threads with NO timeout on Windows). The warm
probe thread then hung holding the module-level _CACHE_LOCK, so every
new session's prompt build blocked indefinitely (#67964).

Two layers:

- _run(): replace subprocess.run with Popen + communicate(timeout); on
  TimeoutExpired kill the process TREE (taskkill /T on Windows) and
  reap the direct child bounded — never re-read the pipes, so an
  orphaned descendant holding them open can't block us.
- get_environment_probe_line(): the probe now runs in a single
  background worker publishing via a threading.Event; callers wait at
  most _PROBE_WAIT_TIMEOUT (10s) then fail open with "". After one
  full timeout, later callers only peek. If the stuck worker ever
  finishes, its line resumes appearing in new prompts.

Regression tests: hung probe with 4 concurrent callers returns bounded;
late recovery publishes; repeat callers skip the wait; _run() returns
promptly despite a pipe-holding descendant (real subprocess E2E).

Fixes #67964
2026-07-20 05:38:20 -07:00

292 lines
12 KiB
Python

"""Tests for tools/env_probe.py — local Python toolchain probe."""
import sys
import pytest
from tools import env_probe
@pytest.fixture(autouse=True)
def reset_probe_cache():
"""Each test starts with a clean cache."""
env_probe._reset_cache_for_tests()
yield
env_probe._reset_cache_for_tests()
class TestSilentWhenHealthy:
"""The probe must emit nothing when the environment is clean — otherwise
every prompt for every user pays an unnecessary token tax."""
def test_clean_env_returns_empty(self, monkeypatch):
"""python3 + pip module + no PEP 668 → silent."""
monkeypatch.setattr(env_probe, "_python_version_of",
lambda b: "3.13.3" if b == "python3" else None)
monkeypatch.setattr(env_probe, "_has_pip_module", lambda b: True)
monkeypatch.setattr(env_probe, "_detect_pep668", lambda b: False)
monkeypatch.setattr(env_probe, "_pip_python_version", lambda: "3.13")
monkeypatch.setattr(env_probe.shutil, "which", lambda name: None)
assert env_probe.get_environment_probe_line() == ""
def test_pep668_with_uv_returns_empty(self, monkeypatch):
"""PEP 668 alone shouldn't trigger output if uv is installed —
agent has a viable install path."""
monkeypatch.setattr(env_probe, "_python_version_of",
lambda b: "3.12.4" if b == "python3" else None)
monkeypatch.setattr(env_probe, "_has_pip_module", lambda b: True)
monkeypatch.setattr(env_probe, "_detect_pep668", lambda b: True)
monkeypatch.setattr(env_probe, "_pip_python_version", lambda: "3.12")
monkeypatch.setattr(env_probe.shutil, "which",
lambda name: "/usr/local/bin/uv" if name == "uv" else None)
assert env_probe.get_environment_probe_line() == ""
class TestEmitsOnRealProblems:
"""The probe must produce a usable line for the real failure modes
that drove this feature."""
def test_allen_scenario_python_version_mismatch(self, monkeypatch):
"""python3 is 3.11 (no pip module), pip on PATH is 3.12, PEP 668 on,
no uv — the exact scenario from the Sarasota real-estate task."""
monkeypatch.setattr(env_probe, "_python_version_of",
lambda b: {"python3": "3.11.15", "python": None}.get(b))
monkeypatch.setattr(env_probe, "_has_pip_module", lambda b: False)
monkeypatch.setattr(env_probe, "_detect_pep668", lambda b: True)
monkeypatch.setattr(env_probe, "_pip_python_version", lambda: "3.12")
monkeypatch.setattr(env_probe.shutil, "which",
lambda name: None if name == "uv" else "/usr/bin/" + name)
line = env_probe.get_environment_probe_line()
assert line # not silent
# Single line — must not blow up the system prompt.
assert "\n" not in line
# Names the real toolchain state
assert "3.11.15" in line
assert "no pip module" in line
assert "mismatch" in line
assert "PEP 668" in line
# Points at the right escape hatch
assert "venv" in line or "uv" in line
def test_missing_python3_is_named(self, monkeypatch):
"""If python3 isn't installed at all, say so."""
monkeypatch.setattr(env_probe, "_python_version_of", lambda b: None)
monkeypatch.setattr(env_probe, "_has_pip_module", lambda b: False)
monkeypatch.setattr(env_probe, "_detect_pep668", lambda b: False)
monkeypatch.setattr(env_probe, "_pip_python_version", lambda: None)
monkeypatch.setattr(env_probe.shutil, "which", lambda name: None)
line = env_probe.get_environment_probe_line()
assert "python3=missing" in line
def test_python_missing_but_python3_present(self, monkeypatch):
"""Common on Debian: only python3 exists, agent shouldn't type
`python`."""
monkeypatch.setattr(env_probe, "_python_version_of",
lambda b: "3.12.4" if b == "python3" else None)
monkeypatch.setattr(env_probe, "_has_pip_module", lambda b: True)
monkeypatch.setattr(env_probe, "_detect_pep668", lambda b: True)
monkeypatch.setattr(env_probe, "_pip_python_version", lambda: "3.12")
monkeypatch.setattr(env_probe.shutil, "which",
lambda name: None if name == "uv" else "/usr/bin/" + name)
line = env_probe.get_environment_probe_line()
# `python=missing` only matters in the non-silent path; PEP 668 (without
# uv) is what brings us off-silent here, so check both signals.
assert "PEP 668" in line
assert "python=missing" in line
class TestSkipsRemoteBackends:
"""Remote backends have their own probe; this one must stay out."""
def test_docker_returns_empty(self, monkeypatch):
monkeypatch.setenv("TERMINAL_ENV", "docker")
# Even with a broken local env, docker must emit nothing.
monkeypatch.setattr(env_probe, "_python_version_of", lambda b: None)
monkeypatch.setattr(env_probe, "_has_pip_module", lambda b: False)
assert env_probe.get_environment_probe_line() == ""
def test_modal_returns_empty(self, monkeypatch):
monkeypatch.setenv("TERMINAL_ENV", "modal")
assert env_probe.get_environment_probe_line() == ""
def test_ssh_returns_empty(self, monkeypatch):
monkeypatch.setenv("TERMINAL_ENV", "ssh")
assert env_probe.get_environment_probe_line() == ""
class TestCaching:
"""The probe runs once per process — the result is deterministic for
the lifetime of the agent."""
def test_result_cached(self, monkeypatch):
calls = []
def counting_version(b):
calls.append(b)
return "3.12.4" if b == "python3" else None
monkeypatch.setattr(env_probe, "_python_version_of", counting_version)
monkeypatch.setattr(env_probe, "_has_pip_module", lambda b: True)
monkeypatch.setattr(env_probe, "_detect_pep668", lambda b: False)
monkeypatch.setattr(env_probe, "_pip_python_version", lambda: "3.12")
monkeypatch.setattr(env_probe.shutil, "which", lambda name: None)
env_probe.get_environment_probe_line()
env_probe.get_environment_probe_line()
env_probe.get_environment_probe_line()
# Only the first call probes — caller-counting confirms it.
# Two calls (python3 + python) on first invocation, zero after.
assert len(calls) == 2
class TestRobustness:
"""The probe must NEVER crash the prompt build."""
def test_subprocess_failure_returns_empty(self, monkeypatch):
"""If every subprocess fails, just stay silent."""
def boom(*a, **kw):
raise OSError("simulated")
monkeypatch.setattr(env_probe.subprocess, "run", boom)
monkeypatch.setattr(env_probe.subprocess, "Popen", boom)
# Should not raise, should just return ""
result = env_probe.get_environment_probe_line()
# Whatever the result is, it must be a string
assert isinstance(result, str)
class TestStuckProbeNeverBlocksCallers:
"""Regression for #67964: on Windows an orphaned pip descendant kept
the probe's capture pipes open, wedging the warm thread inside
subprocess._communicate while it held the module lock — every new
session's prompt build then blocked forever. Callers must fail open
within a bounded time no matter what the probe subprocesses do."""
def test_hung_probe_fails_open_for_concurrent_callers(self, monkeypatch):
"""Concurrent get_environment_probe_line() callers return "" within
a bounded wall-clock time while the probe worker stays stuck."""
import threading as _threading
import time
release = _threading.Event()
def stuck_probe():
# Simulate the wedged pipe read: blocks until released.
release.wait(timeout=30)
return "Python toolchain: late-result."
monkeypatch.setattr(env_probe, "_build_probe_line", stuck_probe)
# Keep the test fast — the bound just has to exist, not be 10s.
monkeypatch.setattr(env_probe, "_PROBE_WAIT_TIMEOUT", 0.5)
env_probe.warm_environment_probe_async()
results: list[str] = []
errors: list[BaseException] = []
def caller():
try:
results.append(env_probe.get_environment_probe_line())
except BaseException as exc: # noqa: BLE001
errors.append(exc)
threads = [_threading.Thread(target=caller, daemon=True) for _ in range(4)]
start = time.monotonic()
for t in threads:
t.start()
for t in threads:
t.join(timeout=10)
elapsed = time.monotonic() - start
try:
assert not errors
assert all(not t.is_alive() for t in threads), "caller blocked on stuck probe"
# All callers failed open with the empty line.
assert results == ["", "", "", ""]
# Bounded: nowhere near the 30s the probe is stuck for.
assert elapsed < 8
finally:
release.set()
def test_late_probe_result_published_after_recovery(self, monkeypatch):
"""If the stuck worker eventually finishes, later callers get the
line — recovery without restart, matching the incident (killing
the orphan un-wedged everything)."""
import threading as _threading
release = _threading.Event()
def slow_probe():
release.wait(timeout=30)
return "Python toolchain: recovered."
monkeypatch.setattr(env_probe, "_build_probe_line", slow_probe)
monkeypatch.setattr(env_probe, "_PROBE_WAIT_TIMEOUT", 0.2)
# First caller times out and fails open.
assert env_probe.get_environment_probe_line() == ""
# Worker un-wedges (the operator killed the orphan).
release.set()
assert env_probe._PROBE_DONE.wait(timeout=10)
# Later callers see the published line.
assert env_probe.get_environment_probe_line() == "Python toolchain: recovered."
def test_repeat_callers_do_not_pay_full_wait_after_first_timeout(self, monkeypatch):
"""After one caller burns the full wait, subsequent callers only
peek — a permanently stuck probe costs the timeout once, not
per-session."""
import threading as _threading
import time
release = _threading.Event()
def stuck_probe():
release.wait(timeout=30)
return ""
monkeypatch.setattr(env_probe, "_build_probe_line", stuck_probe)
monkeypatch.setattr(env_probe, "_PROBE_WAIT_TIMEOUT", 0.5)
try:
assert env_probe.get_environment_probe_line() == "" # pays 0.5s
# Crank the timeout way up: if the peek short-circuit is broken,
# the next call blocks ~30s; if it works, it returns in ~0.05s.
monkeypatch.setattr(env_probe, "_PROBE_WAIT_TIMEOUT", 30.0)
start = time.monotonic()
assert env_probe.get_environment_probe_line() == ""
assert time.monotonic() - start < 5 # peek, not a full wait
finally:
release.set()
class TestRunTimeoutIsBounded:
"""_run() itself must return within a bounded time even when the child
spawns a descendant that inherits the capture pipes and outlives it —
the exact Windows pip.exe launcher shape from #67964, reproduced
cross-platform with a shell child."""
def test_run_returns_promptly_despite_pipe_holding_descendant(self):
import time
# Child exits quickly; grandchild inherits stdout/stderr and sleeps
# far beyond the timeout, keeping the pipe write-ends open.
script = (
"import subprocess, sys, time\n"
"subprocess.Popen([sys.executable, '-c', 'import time; time.sleep(20)'])\n"
"time.sleep(20)\n"
)
start = time.monotonic()
rc, out, err = env_probe._run([sys.executable, "-c", script], timeout=1.0)
elapsed = time.monotonic() - start
assert rc == -1
assert err == "timeout"
# stdlib subprocess.run on Windows would hang here for the full 20s
# (unbounded post-kill communicate). Our bound: timeout + reap slack.
assert elapsed < 6