Stack crash when trying to stop on an PyTest breakpoint

[WibblyGhost]

When running a debug point on a pytest function, when the executor enters the breakpoint, it immediately crashes.

Found with debugpy == 2024.12.0
Version: 1.95.3 (system setup)
Commit: f1a4fb101478ce6ec82fe9627c43efbf9e98c813
Date: 2024-11-13T14:50:04.152Z
Electron: 32.2.1
ElectronBuildId: 10427718
Chromium: 128.0.6613.186
Node.js: 20.18.0
V8: 12.8.374.38-electron.0
OS: Windows_NT x64 10.0.19045

{
            "name": "Python: Debug Tests",
            "type": "debugpy",
            "request": "launch",
            "program": "${file}",
            "purpose": ["debug-test"],
            "console": "integratedTerminal",
            "justMyCode": false,
            "env": {
                "PYTEST_ADDOPTS": "--no-cov"
            }
        }

Trying to run this test on python 3.12
pip list
Package Version

---

aiofiles 24.1.0
aiohappyeyeballs 2.4.0
aiohttp 3.11.7
aiosignal 1.3.1
astroid 3.3.5
attrs 24.2.0
black 24.10.0
certifi 2024.7.4
cfgv 3.4.0
charset-normalizer 3.3.2
click 8.1.7
colorama 0.4.6
construct 2.10.70
coverage 7.6.1
dill 0.3.8
distlib 0.3.8
Faker 33.0.0
filelock 3.15.4
flake8 7.1.1
frozenlist 1.4.1
identify 2.6.0
idna 3.8
iniconfig 2.0.0
isort 5.13.2
mccabe 0.7.0
mock 5.1.0
multidict 6.0.5
mypy 1.13.0
mypy-extensions 1.0.0
nodeenv 1.9.1
p25codecs 2.6.2
p25simulatorcommon 1.2.2
packaging 24.1
pathspec 0.12.1
pip 24.3.1
platformdirs 4.2.2
pluggy 1.5.0
pre_commit 4.0.1
prettier 0.0.7
progress 1.6
propcache 0.2.0
pycodestyle 2.12.1
pyflakes 3.2.0
pylint 3.3.1
pytest 8.3.3
pytest-asyncio 0.24.0
pytest-cov 6.0.0
pytest-mock 3.14.0
pytest-timeout 2.3.1
python-dateutil 2.9.0.post0
PyYAML 6.0.2
reedsolo 1.7.0
requests 2.32.3
scapy 2.5.0
six 1.16.0
termcolor 2.3.0
tomlkit 0.13.2
tqdm 4.67.1
types-aiofiles 24.1.0.20240626
types-requests 2.32.0.20241016
typing_extensions 4.12.2
urllib3 2.2.2
virtualenv 20.26.3
vulture 2.13
yarl 1.18.0
yaspin 3.0.2

@mark.asyncio
async def test_send_retries_on_too_many_requests(
    mocker: MockerFixture,
    wui_fixture: AsyncWuiClient,
    request_fixture: AsyncMock,
    caplog: LogCaptureFixture,
) -> None:
    # Define
    async with wui_fixture as client:
        kwargs_ = wui_fixture._create_kwargs(target_url=TEST_TARGET_URL)  # Already been tested
    response_1 = ResponseGenerator(status_code=429, method=TEST_GET).prepare()
    response_2 = ResponseGenerator(status_code=200, method=TEST_GET).prepare()

    # Setup/Mock
    caplog.set_level(WARNING)
    sleep_ = mocker.patch("src.async_wui.base.wui_client.sleep", return_value=mocker.async_stub())  <---- breakpoint set

taitnet@Zac-Dev:~/Programming/wui_clients$  /usr/bin/env /home/taitnet/Programming/wui_clients/.venv3/bin/python /home/taitnet/.vscode-server/extensions/ms-python.debugpy-2024.12.0-linux-x64/bundled/libs/debugpy/adapter/../../debugpy/launcher 39941 -- /home/taitnet/.vscode-server/extensions/ms-python.python-2024.20.0-linux-x64/python_files/vscode_pytest/run_pytest_script.py --rootdir=/home/taitnet/Programming/wui_clients --capture=no 
Running pytest with args: ['-p', 'vscode_pytest', '--rootdir=/home/taitnet/Programming/wui_clients', '--capture=no', '/home/taitnet/Programming/wui_clients/tests/async_wui/base/test_async_wui_client.py::test_send_retries_on_too_many_requests']
============================= test session starts ==============================
platform linux -- Python 3.12.3, pytest-8.3.3, pluggy-1.5.0
rootdir: /home/taitnet/Programming/wui_clients
configfile: pyproject.toml
plugins: timeout-2.3.1, mock-3.14.0, cov-6.0.0, asyncio-0.24.0, Faker-33.0.0
timeout: 0.25s
timeout method: signal
timeout func_only: False
asyncio: mode=Mode.STRICT, default_loop_scope=function
collected 1 item

tests/async_wui/base/test_async_wui_client.py ~~~~~~~~~~~~~~~~~~~~~ Stack of <unknown> (132507030783680) ~~~~~~~~~~~~~~~~~~~~~
  File "/usr/lib/python3.12/threading.py", line 1030, in _bootstrap
    self._bootstrap_inner()
  File "/usr/lib/python3.12/threading.py", line 1073, in _bootstrap_inner
    self.run()
  File "/home/taitnet/.vscode-server/extensions/ms-python.debugpy-2024.12.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_daemon_thread.py", line 53, in run
    self._on_run()
  File "/home/taitnet/.vscode-server/extensions/ms-python.debugpy-2024.12.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/pydevd.py", line 325, in _on_run
    self._wait_event.wait(TIMEOUT_SLOW)
  File "/usr/lib/python3.12/threading.py", line 655, in wait
    signaled = self._cond.wait(timeout)
  File "/usr/lib/python3.12/threading.py", line 359, in wait
    gotit = waiter.acquire(True, timeout)
~~~~~~~~~~~~~~~~~~~~~ Stack of <unknown> (132507041269440) ~~~~~~~~~~~~~~~~~~~~~
  File "/usr/lib/python3.12/threading.py", line 1030, in _bootstrap
    self._bootstrap_inner()
  File "/usr/lib/python3.12/threading.py", line 1073, in _bootstrap_inner
    self.run()
  File "/home/taitnet/.vscode-server/extensions/ms-python.debugpy-2024.12.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_daemon_thread.py", line 53, in run
    self._on_run()
  File "/home/taitnet/.vscode-server/extensions/ms-python.debugpy-2024.12.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/pydevd.py", line 280, in _on_run
    self._py_db_command_thread_event.wait(TIMEOUT_SLOW)
  File "/usr/lib/python3.12/threading.py", line 655, in wait
    signaled = self._cond.wait(timeout)
  File "/usr/lib/python3.12/threading.py", line 359, in wait
    gotit = waiter.acquire(True, timeout)
~~~~~~~~~~~~~~~~~~~~~ Stack of <unknown> (132507051755200) ~~~~~~~~~~~~~~~~~~~~~
  File "/usr/lib/python3.12/threading.py", line 1030, in _bootstrap
    self._bootstrap_inner()
  File "/usr/lib/python3.12/threading.py", line 1073, in _bootstrap_inner
    self.run()
  File "/home/taitnet/.vscode-server/extensions/ms-python.debugpy-2024.12.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_daemon_thread.py", line 53, in run
    self._on_run()
  File "/home/taitnet/.vscode-server/extensions/ms-python.debugpy-2024.12.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py", line 245, in _on_run
    line = self._read_line()
  File "/home/taitnet/.vscode-server/extensions/ms-python.debugpy-2024.12.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py", line 227, in _read_line
    r = self.sock.recv(1024)
~~~~~~~~~~~~~~~~~~~~~ Stack of <unknown> (132507062240960) ~~~~~~~~~~~~~~~~~~~~~
  File "/usr/lib/python3.12/threading.py", line 1030, in _bootstrap
    self._bootstrap_inner()
  File "/usr/lib/python3.12/threading.py", line 1073, in _bootstrap_inner
    self.run()
  File "/home/taitnet/.vscode-server/extensions/ms-python.debugpy-2024.12.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_daemon_thread.py", line 53, in run
    self._on_run()
  File "/home/taitnet/.vscode-server/extensions/ms-python.debugpy-2024.12.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_comm.py", line 390, in _on_run
    cmd = self._cmd_queue.get(True, 0.1)
  File "/usr/lib/python3.12/queue.py", line 180, in get
    self.not_empty.wait(remaining)
  File "/usr/lib/python3.12/threading.py", line 359, in wait
    gotit = waiter.acquire(True, timeout)

[rchiodo]

I would hazard a guess that the test is messing up something that pydevd uses to do the waiting, but we'd need a full repro to be sure.

Can you include all of the source to get this test to run?

[WibblyGhost]

@rchiodo I believe the culprit is the module pytest-timeout interfering with the thread and sending a kill cmd.
https://pypi.org/project/pytest-timeout/

You can reproduce it on any unit test involving this plugin.

@mark.timeout(60)
def test_truthy() -> None:
    assert True == False

The plugin didn't use to cause issues, although maybe something in the plugin or VSCode has changed.

Maybe this can help from their docs.

Debugger Detection.
This plugin tries to avoid triggering the timeout when a debugger is detected. This is mostly a convenience so you do not need to remember to disable the timeout when interactively debugging.
.The way this plugin detects whether or not a debugging session is active is by checking if a trace function is set and if one is, it check to see if the module it belongs to is present in a set of known debugging frameworks modules OR if pytest itself drops you into a pdb session using --pdb or similar.

[WibblyGhost]

Could be related to this issue?
pytest-dev/pytest-timeout#152

[rchiodo]

The way this plugin detects whether or not a debugging session is active is by checking if a trace function is set

This likely doesn't work anymore because we don't use sys.trace anymore after 3.12 added sys.monitor. I would hazard a guess pytest-timeout needs to check for sys.monitor now.

Does your debugging work with 3.11?

[WibblyGhost]

@rchiodo yes it seems to work fine in Python 3.11 but not 3.12.
Their release notes claim this issue is fixed in october, but I still receive this issue on 2.3.1.

2.3.0
Fix debugger detection for recent VSCode, this compiles pydevd using cython which is now correctly detected. Thanks Adrian Gielniewski.

Maybe you could help contact someone from the pytest-timeout community to have some input to this?

[rchiodo]

This code here definitely doesn't detect sys.monitoring:

https://github.com/pytest-dev/pytest-timeout/blob/3d41ba8042ab1d07613572d95853dcc1c3602880/pytest_timeout.py#L281

I'll log an issue on pytest-timeout.

[rchiodo]

Logged this issue:
pytest-dev/pytest-timeout#182