FileNotFoundError when discovering tests

[kwood]

Type: Bug

Behaviour

Expected vs. Actual

Expected: Pytest should be able to discover tests on the devcontainer
Actual: Python extension throws an error trying to read a tempfile it created, and no tests are discovered.

Steps to reproduce:

I'm not certain how to build a minimum reproduction case here—this is a Django project running in a devcontainer. I can run pytest just fine inside the container, and the exception is thrown inside python extension code.

Diagnostic data

• Python version (& distribution if applicable, e.g. Anaconda): 3.11.8
• Type of virtual environment used (e.g. conda, venv, virtualenv, etc.): Global
• Value of the python.languageServer setting: Default

Output for Python in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python)

2024-02-21 15:25:12.197 [error] Error discovering pytest tests:
 n [Error]: Traceback (most recent call last):
  File "/home/eb/.vscode-server/extensions/ms-python.python-2024.0.1/pythonFiles/testing_tools/run_adapter.py", line 22, in <module>
    main(tool, cmd, subargs, toolargs)
  File "/home/eb/.vscode-server/extensions/ms-python.python-2024.0.1/pythonFiles/testing_tools/adapter/__main__.py", line 99, in main
    parents, result = run(toolargs, **subargs)
                      ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/eb/.vscode-server/extensions/ms-python.python-2024.0.1/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 29, in discover
    with util.hide_stdio() if hidestdio else util.noop_cm() as stdio:
  File "/usr/local/lib/python3.11/contextlib.py", line 144, in __exit__
    next(self.gen)
  File "/home/eb/.vscode-server/extensions/ms-python.python-2024.0.1/pythonFiles/testing_tools/adapter/util.py", line 251, in hide_stdio
    with _temp_io() as (sio, fileobj):
  File "/usr/local/lib/python3.11/contextlib.py", line 144, in __exit__
    next(self.gen)
  File "/home/eb/.vscode-server/extensions/ms-python.python-2024.0.1/pythonFiles/testing_tools/adapter/util.py", line 244, in _temp_io
    buff = tmp.read()
           ^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory

User Settings

languageServer: "Pylance"

testing
• pytestArgs: "<placeholder>"
• pytestEnabled: true
• unittestArgs: "<placeholder>"

experiments
• enabled: false

Extension version: 2024.0.1
VS Code version: Code 1.86.2 (903b1e9d8990623e3d7da1df3d33db3e42d80eda, 2024-02-13T19:42:12.210Z)
OS version: Darwin arm64 23.1.0
Modes:
Remote OS version: Linux arm64 6.6.12-linuxkit

System Info

Item	Value
CPUs	Apple M2 Max (12 x 24)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: enabled webgl: enabled webgl2: enabled webgpu: enabled
Load (avg)	2, 3, 5
Memory (System)	32.00GB (0.06GB free)
Process Argv	--crash-reporter-id 96ee63c6-c076-4359-87ab-090974f46b78
Screen Reader	no
VM	0%

Item	Value
Remote	Dev Container: backend_dev @ desktop-linux
OS	Linux arm64 6.6.12-linuxkit
CPUs	unknown (12 x 0)
Memory (System)	15.60GB (12.20GB free)
VM	0%

A/B Experiments

vsliv368:30146709
vspor879:30202332
vspor708:30202333
vspor363:30204092
vscoreces:30445986
vscod805:30301674
binariesv615:30325510
vsaa593cf:30376535
py29gd2263:30899288
c4g48928:30535728
azure-dev_surveyonecf:30548226
2i9eh265:30646982
962ge761:30959799
pythongtdpath:30769146
welcomedialog:30910333
pythonidxpt:30866567
pythonnoceb:30805159
asynctok:30898717
pythontestfixt:30902429
pythonregdiag2:30936856
pyreplss1:30897532
pythonmypyd1:30879173
pythoncet0:30885854
2e7ec940:30968132
pythontbext0:30879054
dsvsc016:30899300
dsvsc017:30899301
dsvsc018:30899302
edj9j583:30969295
fegfb526:30961430
7j2b6412:30969109
bg6jg535:30958357

[eleanorjboyd]

Hello! It looks like you are on the old version of testing due to the path referenced -2024.0.1/pythonFiles/testing_tools/adapter/pytest/_discovery.py". Can you see if in your user settings you have disabled python experiments? You can also add "python.experiments.optInto": [
"pythonTestAdapter"
],

if you do this an reload, then you should see a different path / set of logs. See if that works, if not then please send me to logs from that run.

Thanks!

[kwood]

Yes, we have experiments disabled because of #22383

Our tests need to have sockets disabled, but it looks like if we upgrade pytest-socket and allow localhost we should be OK. Thanks for the help.