pytest test discovery not working

[radu-ion]

Type: Bug

Behaviour

Test discovery in folder 'tests' ends with this error message:

2025-09-19 11:46:07.380 [info] Native locator: Refresh started
2025-09-19 11:46:07.380 [info] Native locator: Refresh started
2025-09-19 11:46:07.501 [info] Native locator: Refresh finished in 121 ms
2025-0
9-19 11:46:07.508 [info] > pyenv which python
2025-09-19 11:46:07.508 [info] cwd: .
2025-09-19 11:46:07.528 [info] Active interpreter [e:\Temp\test_problem]: C:\Program Files\Python312\python.exe
2025-09-19 11:46:07.530 [info] Starting Pylance language server.
2025-09-19 11:46:13.475 [info] Discover tests for workspace name: test_problem - uri: e:\Temp\test_problem
2025-09-19 11:46:13.476 [warning] The cwd resolves to a different path, checking if it has a symbolic link somewhere in its path.
2025-09-19 11:46:13.477 [info] Environment variables set for pytest discovery: PYTHONPATH=c:\Users\ionra.vscode\extensions\ms-python.python-2025.14.0-win32-x64\python_files, TEST_RUN_PIPE=\.\pipe\python-test-discovery-aeac70e13732cd3eded9
2025-09-19 11:46:13.493 [error] Subprocess exited unsuccessfully with exit code null and signal null on workspace e:\Temp\test_problem
2025-09-19 11:46:13.493 [error] pytest test discovery error for workspace: e:\Temp\test_problem

The python test process was terminated before it could exit on its own, the process errored with: Code: null, Signal: null for workspace e:\Temp\test_problem

Steps to reproduce:

1. Create an empty folder with any test case in the 'tests' folder.
2. Click on the testing icon in the left toolbar of VS Code.
3. See the output of test discovery.

Or you can try with the attached project.
test_problem.zip

Extension version: 2025.14.0
VS Code version: Code 1.104.1 (0f0d87fa9e96c856c5212fc86db137ac0d783365, 2025-09-17T23:36:24.973Z)
OS version: Windows_NT x64 10.0.26100
Modes:

• Python version (& distribution if applicable, e.g. Anaconda): 3.12.7
• Type of virtual environment used (e.g. conda, venv, virtualenv, etc.): System
• Value of the python.languageServer setting: Default

User Settings

languageServer: "Pylance"

Installed Extensions

Extension Name	Extension Id	Version
autopep8	ms-	2025.2.0
cmake-tools	ms-	1.21.36
cpptools	ms-	1.27.7
cpptools-extension-pack	ms-	1.3.1
cpptools-themes	ms-	2.0.0
debugpy	ms-	2025.10.0
docker	doc	0.17.0
intellicode-api-usage-examples	Vis	0.2.9
isort	ms-	2025.0.0
java	red	1.45.0
js-debug	ms-	1.104.0
js-debug-companion	ms-	1.1.3
python	ms-	2025.14.0
remote-containers	ms-	0.427.0
remote-wsl	ms-	0.104.2
vscode-containers	ms-	2.1.0
vscode-docker	ms-	2.0.0
vscode-gradle	vsc	3.17.0
vscode-java-debug	vsc	0.58.2
vscode-java-dependency	vsc	0.24.1
vscode-java-pack	vsc	0.29.2
vscode-java-test	vsc	0.43.1
vscode-js-profile-table	ms-	1.0.10
vscode-maven	vsc	0.44.0
vscode-pylance	ms-	2025.8.2
vscode-python-envs	ms-	1.8.0
vscodeintellicode	Vis	1.3.2
xml	Dot	2.5.1

System Info

Item	Value
CPUs	Intel(R) Core(TM) i9-14900K (32 x 3187)
GPU Status	2d_canvas: enabled 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 trees_in_viz: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	127.79GB (104.94GB free)
Process Argv	--crash-reporter-id c3e6123c-0326-4a4a-abe1-126bd33ddb9e
Screen Reader	no
VM	0%

A/B Experiments

vsliv368:30146709
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
996jf627:31283433
pythonrdcb7:31342333
usemplatestapi:31297334
aj953862:31281341
nesew2to5:31336538
cs4_fixed:31388788
nes-set-on:31351930
6abeh943:31336334
envsactivate1:31353494
0927b901:31350571
ovs_t:31383295
editstats-enabled:31346257
aa_t:31379598
0cj2b977:31352657
0574c672:31362109
cloudbuttont:31379625
todos-1:31384886
codex-prompt:31370221
multireplacestringcontrol:31387919
control_gpt5applypatchexclusively:31387916
3efgi100_wstrepl:31382709
metis-embeddings:31388492
trigger-command-fix:31379601
auto_model_enabled:31385282

[eleanorjboyd]

Hi! This is a duplicate of #25474 please check out that issue as I look to resolve the problem. Thanks!