Test discovery fails

[cmbryan]

Type: Bug

Behaviour

Test discovery fails, as previously reported here: #24656

Steps to reproduce:

1. Poetry project with Python 3.12 and Poetry on Ubuntu 24.04

Diagnostic data

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

2025-04-11 17:24:50.251 [info] Discover tests for workspace name: d6 - uri: /home/chris/Documents/d6/d6_api/models.py
2025-04-11 17:24:51.849 [info] Discover tests for workspace name: d6 - uri: /home/chris/Documents/d6/d6_api/models.py
2025-04-11 17:24:51.849 [error] Test discovery already in progress, not starting a new one.
2025-04-11 17:28:33.107 [info] Discover tests for workspace name: d6 - uri: /home/chris/Documents/d6
2025-04-11 17:28:33.107 [error] Test discovery already in progress, not starting a new one.
2025-04-11 18:01:09.682 [info] Running installed packages checker:  {
  id: '/home/chris/Documents/d6/.venv/bin/python',
  sysPrefix: '/home/chris/Documents/d6/.venv',
  envType: 'Poetry',
  envName: '.venv',
  envPath: '/home/chris/Documents/d6/.venv',
  path: '/home/chris/Documents/d6/.venv/bin/python',
  architecture: 3,
  sysVersion: '3.10.12 (main, Feb  4 2025, 14:57:36) [GCC 11.4.0]',
  version: {
    raw: '3.10.12',
    major: 3,
    minor: 10,
    patch: 12,
    build: [],
    prerelease: [ 'final', '0' ]
  },
  displayName: "Python 3.10.12 ('.venv')",
  detailedDisplayName: "Python 3.10.12 ('.venv': Poetry)",
  type: 'Virtual'
} /home/chris/.vscode/extensions/ms-python.python-2025.0.0-linux-x64/python_files/installed_check.py /home/chris/Documents/d6/pyproject.toml

Extension version: 2025.4.0
VS Code version: Code 1.98.2 (ddc367ed5c8936efe395cffeec279b04ffd7db78, 2025-03-12T13:32:45.399Z)
OS version: Linux x64 5.19.0-50-generic
Modes:

• Python version (& distribution if applicable, e.g. Anaconda): 3.10.12
• Type of virtual environment used (e.g. conda, venv, virtualenv, etc.): Poetry
• Value of the python.languageServer setting: Default

User Settings

languageServer: "Pylance"

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

Installed Extensions

Extension Name	Extension Id	Version
autodocstring	njp	0.6.1
debugpy	ms-	2025.6.0
even-better-toml	tam	0.21.2
geminicodeassist	goo	2.30.3
github-vscode-theme	Git	6.3.5
js-debug	ms-	1.97.1
js-debug-companion	ms-	1.1.3
jupyter	ms-	2025.2.2025021801
jupyter-keymap	ms-	1.1.2
jupyter-renderers	ms-	1.1.2025012901
makefile-tools	ms-	0.12.17
python	ms-	2025.0.0
python-environment-manager	don	1.2.7
remote-containers	ms-	0.406.0
remote-explorer	ms-	0.4.3
remote-server	ms-	1.5.2
remote-ssh	ms-	0.119.0
remote-ssh-edit	ms-	0.87.0
remote-wsl	ms-	0.88.5
ruff	cha	2025.22.0
vim	vsc	1.29.0
vim-cheatsheet	And	0.0.1
vscode-docker	ms-	1.29.5
vscode-js-profile-table	ms-	1.0.10
vscode-jupyter-cell-tags	ms-	0.1.9
vscode-jupyter-slideshow	ms-	0.1.6
vscode-markdownlint	Dav	0.59.0
vscode-pylance	ms-	2025.3.2
vscode-remote-extensionpack	ms-	0.26.0
vscode-sqlite	ale	0.14.1
vscode-sundial	muu	3.5.1

System Info

Item	Value
CPUs	11th Gen Intel(R) Core(TM) i7-11850H @ 2.50GHz (16 x 3690)
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: disabled_software vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: disabled_off webnn: disabled_off
Load (avg)	1, 2, 2
Memory (System)	31.07GB (1.37GB free)
Process Argv	--crash-reporter-id 124560b1-dba2-4028-aaf7-29726069cfd0
Screen Reader	no
VM	0%
DESKTOP_SESSION	ubuntu-xorg
XDG_CURRENT_DESKTOP	Unity
XDG_SESSION_DESKTOP	ubuntu-xorg
XDG_SESSION_TYPE	x11

A/B Experiments

vsliv368:30146709
vspor879:30202332
vspor708:30202333
vspor363:30204092
vscod805:30301674
binariesv615:30325510
c4g48928:30535728
azure-dev_surveyone:30548225
962ge761:30959799
h48ei257:31000450
pythontbext0:30879054
cppperfnew:31000557
dwnewjupyter:31046869
pythonrstrctxt:31112756
nativeloc1:31192215
5fd0e150:31155592
dwcopilot:31170013
6074i472:31201624
dwoutputs:31242946
customenabled:31248079
9064b325:31222308
copilot_t_ci:31222730
968h8231:31277804
cp15370_c:31280196
pythoneinst12cf:31262606
bgtreat:31268568
4gafe986:31271826
31787653:31262186
3e8i5726:31271747
996jf627:31281244
useunpkgapi:31280918
g20af354:31278749
d31a3264:31280423
aj953862:31281341

[dean-redelinghuys]

For me the behaviour is slightly different from #24656 but effect is the same: Test discovery succeeds (output window shows all tests being collected) but the Test panel remains at the "No tests are configured" dialog.

[caioolivv]

I'm having a similar problem, discover starts and never finishes:

2025-05-16 12:16:17.881 [info] Discover tests for workspace name: Workspace - uri: /home/user/Workspace
2025-05-16 12:16:18.803 [info] Environment variables set for pytest discovery: PYTHONPATH=/home/user/.vscode/extensions/ms-python.python-2025.7.2025051601-linux-x64/python_files, TEST_RUN_PIPE=/run/user/1000/python-test-discovery-ec759c845184788e6d85

ms-python version: 2025.7.2025051601

[practual]

Same issue, using any version of the extension 2025.X.X - last working version was 20254.22.2 as per #24656

Running in WSL, with a single pytest test, and settings:

{
    "python.experiments.optOutFrom": [
        "All"
    ],
    "python.testing.pytestArgs": [
        "test"
    ],
    "python.testing.unittestEnabled": false,
    "python.testing.pytestEnabled": true
}

Python interpreter path selected: ./.venv/bin/python (3.11 - installed with pyenv)

Python output when working:

2025-05-29 11:01:31.919 [info] Native locator: Refresh started
2025-05-29 11:01:31.919 [info] Native locator: Refresh started
2025-05-29 11:01:31.952 [info] > ~/.pyenv/bin/pyenv which python
2025-05-29 11:01:31.952 [info] cwd: .
2025-05-29 11:01:32.038 [info] Poetry environment manager found at: /home/phil/.pyenv/shims/poetry
2025-05-29 11:01:32.047 [info] Pyenv environment manager found at: /home/phil/.pyenv/bin/pyenv
2025-05-29 11:01:32.111 [info] Python interpreter path: ./.venv/bin/python
2025-05-29 11:01:35.647 [info] Starting Pylance language server.
2025-05-29 11:01:37.843 [info] Native locator: Refresh finished in 6394 ms
2025-05-29 11:01:40.980 [info] Discover tests for workspace name: test-repo - uri: /home/phil/dev/test-repo
2025-05-29 11:01:41.091 [info] > . ./.venv/bin/activate && echo 'e8b39361-0157-4923-80e1-22d70d46dee6' && python ~/.vscode-server/extensions/ms-python.python-2024.22.2-linux-x64/python_files/printEnvVariables.py
2025-05-29 11:01:41.091 [info] shell: bash
2025-05-29 11:01:41.138 [info] > ./.venv/bin/python ~/.vscode-server/extensions/ms-python.python-2024.22.2-linux-x64/python_files/testing_tools/run_adapter.py discover pytest -- --rootdir . -s --cache-clear test
2025-05-29 11:01:41.138 [info] cwd: .

Python output when not working:

2025-05-29 12:01:05.888 [info] Native locator: Refresh started
2025-05-29 12:01:05.888 [info] Native locator: Refresh started
2025-05-29 12:01:05.928 [info] > ~/.pyenv/bin/pyenv which python
2025-05-29 12:01:05.928 [info] cwd: .
2025-05-29 12:01:05.975 [info] Poetry environment manager found at: /home/phil/.pyenv/shims/poetry
2025-05-29 12:01:06.013 [info] Pyenv environment manager found at: /home/phil/.pyenv/bin/pyenv
2025-05-29 12:01:06.084 [info] Python interpreter path: ./.venv/bin/python
2025-05-29 12:01:09.290 [info] Starting Pylance language server.
2025-05-29 12:01:11.431 [info] Native locator: Refresh finished in 6116 ms
2025-05-29 12:01:59.577 [info] Discover tests for workspace name: test-repo - uri: /home/phil/dev/test-repo

[dean-redelinghuys]

For me the behaviour is slightly different from #24656 but effect is the same: Test discovery succeeds (output window shows all tests being collected) but the Test panel remains at the "No tests are configured" dialog.

This seems to have recurred in 2025.8.0, or maybe even 2025.6.0. Rolling back to 2024.22.2 fixes the panel but removes the coverage option.

[eleanorjboyd]

Hello! Is anyone able to send me a minimal repro so I can try this myself on my computer and catch where the issue might be occurring? @dean-redelinghuys it seems like you had a small example when it worked. Would need the python code / tests, any settings from python.testing.pytestArgs then any other details such a remote machine etc. Thanks!

[dean-redelinghuys]

Hello! Is anyone able to send me a minimal repro so I can try this myself on my computer and catch where the issue might be occurring? @dean-redelinghuys it seems like you had a small example when it worked. Would need the python code / tests, any settings from python.testing.pytestArgs then any other details such a remote machine etc. Thanks!

Hi @eleanorjboyd, I was able to reproduce this behaviour using the small "Intro to Pytest" repo here: https://github.com/pluralsight/intro-to-pytest/

No special settings on my end, except to set the pytest settings to "test". Just clone the repo configure for pytest, use the "test" folder, and it finds all the tests but keeps the panel in the "configure python tests" mode. Downgrade Python extension to 2024.22.2 and it works (but without the coverage button).

[dean-redelinghuys]

@eleanorjboyd something strange is happening with my VSCode. This issue appears to be sporadic but slightly sticky. My test discovery now works for 2025.8.0!

I'm sure I turned off automatic updating for both VSCode and the Python extension, so should be running the same versions as when I reported last week (VSCode 1.101.2). I just on a whim upgraded the Python package to 2025.4.0 and test discovery worked, and then updating to 2025.8.0 test discovery worked. So the issue appears to happen sometimes but not always.

I tested on multiple repos and they all work now. I don't know what changed between then and now. I am now keeping a record of when this issue occurs.

Full VSCode About output:

Version: 1.101.2 (Universal)
Commit: 2901c5ac6db8a986a5666c3af51ff804d05af0d4
Date: 2025-06-24T20:27:15.391Z
Electron: 35.5.1
ElectronBuildId: 11727614
Chromium: 134.0.6998.205
Node.js: 22.15.1
V8: 13.4.114.21-electron.0
OS: Darwin arm64 24.5.0

[github-actions]

Hey @eleanorjboyd, this issue might need further attention.

@cmbryan, you can help us out by closing this issue if the problem no longer exists, or adding more information.

[cmiller73084]

I'm also having this issue similar to #24656

I'm running into this (or a extremely similar) issue. code-server: 4.100.3, Code 1.100.3. Python extension: 2025.4.0.

Test discovery hangs with this in the output log

2025-07-02 14:49:58.649 [debug] Testing: Refreshing all test data
2025-07-02 14:49:58.650 [debug] Found cached env for /home/cwmiller/pytest_vscode/.venv/bin/python
2025-07-02 14:49:58.650 [info] Discover tests for workspace name: pytest_vscode - uri: /home/cwmiller/pytest_vscode
2025-07-02 14:49:58.650 [debug] Found cached env for /home/cwmiller/pytest_vscode/.venv/bin/python
2025-07-02 14:49:58.653 [debug] Starting Test Discovery named pipe
2025-07-02 14:50:15.287 [debug] Found cached env for ...

[patrick-csliu]

No tests have been found, but I have tests in my working directory.

demo_project/
│── demo/
│   ├── __init__.py
│   └── calculator.py
│
│── tests/
│   ├── __init__.py
│   └── test_calculator.py

# test_calculator.py
from demo import calculator

def test_add():
    assert calculator.add(2, 3) == 5

def test_subtract():
    assert calculator.subtract(5, 3) == 2

def test_multiply():
    assert calculator.multiply(4, 3) == 12

def test_divide():
    assert calculator.divide(10, 2) == 5

def test_divide_by_zero():
    import pytest
    with pytest.raises(ValueError):
        calculator.divide(5, 0)

settings.json

{
    "python-envs.defaultEnvManager": "ms-python.python:conda",
    "python-envs.defaultPackageManager": "ms-python.python:conda",
    "python-envs.pythonProjects": [],
    "python.testing.pytestArgs": [
        "tests"
    ],
    "python.testing.unittestEnabled": false,
    "python.testing.pytestEnabled": true,
    "python.testing.autoTestDiscoverOnSaveEnabled": true,

    "python.experiments.optOutFrom": [
        "All"
    ],
}

> pip list
Package    Version
---------- -------
colorama   0.4.6
iniconfig  2.1.0
packaging  25.0
pip        25.1
pluggy     1.6.0
Pygments   2.19.2
pytest     8.4.1
setuptools 78.1.1
wheel      0.45.1

Version: 1.103.2 (user setup)
Commit: 6f17636121051a53c88d3e605c491d22af2ba755
Date: 2025-08-20T16:45:34.255Z
Electron: 37.2.3
ElectronBuildId: 12035395
Chromium: 138.0.7204.100
Node.js: 22.17.0
V8: 13.8.500258-electron.0
OS: Windows_NT x64 10.0.26100

Extension:

Identifier
ms-python.python
Version
2025.12.0

Python ouput:

2025-08-23 18:43:26.165 [info] Discover tests for workspace name: test2 - uri: d:\Projects\test2
2025-08-23 18:43:26.166 [warning] The cwd resolves to a different path, checking if it has a symbolic link somewhere in its path.
2025-08-23 18:43:26.167 [info] arg: --rootdir already exists in args, not adding.
2025-08-23 18:43:26.167 [info] Environment variables set for pytest discovery: PYTHONPATH=c:\Users\01pat\.vscode\extensions\ms-python.python-2025.12.0-win32-x64\python_files, TEST_RUN_PIPE=\\.\pipe\python-test-discovery-ad1b5ab7db433e859b34
2025-08-23 18:46:02.272 [info] Test discovery cancelled.
2025-08-23 18:46:02.272 [info] Test discovery cancelled, killing pytest subprocess for workspace d:\Projects\test2

I can provide more information or the whole folder if that would help, @eleanorjboyd.

[olegsheyner]

@eleanorjboyd The issue reproduces for me as well in version 2025.12.0. Reverting to 2024.22.1 fixes the problem, I tried several releases between 2024.22.1 and 2025.12.0, they all exhibit the problem: test discovery hangs forever after printing

2025-08-26 14:22:43.011 [debug] Running pytest discovery with command: -m pytest -p vscode_pytest --collect-only tests --rootdir=[...] for workspace [...].