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