Python Extension Fails to Auto-Detect Venv on SMB Network Drive #25526

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Type: Bug

Hi all

Issue Title:
Python Extension Fails to Auto-Detect Venv on SMB Network Drive (Z:) with ENOENT Scandir Error in AppData

Environment

• VS Code Version: 1.95.0 (or latest as of October 13, 2025)
• Python Extension Version: 2025.16.0
• Python Version: 3.13.4 (global and in venv)
• OS and Version: Windows 11 (or your version), 64-bit
• Relevant Extensions: ms-python.python (2025.16.0), ms-python.debugpy (2025.14.0), ms-python.pylance (2025.8.3)
• Other Info: Project on SMB-mapped network drive (Z:, not local C:). No Poetry/Conda/Pixi used – plain python -m venv .venv.

Steps to Reproduce

1. Create a new project folder on a network drive, e.g., Z:\0400 Dokumentation\0001 IT Dokumentation\0001 Skripte\PY_Test_with_GROK.
2. In PowerShell (project root): python -m venv .venv (creates venv successfully; Test-Path .\.venv\Scripts\python.exe returns True).
3. Activate venv: .\.venv\Scripts\Activate.ps1 > pip install requests > Deactivate. (Venv works: python -c "import requests; print(requests.__version__)" outputs 2.32.5.)
4. Create .vscode/settings.json:

   {
       "python.defaultInterpreterPath": "./.venv/Scripts/python.exe",
       "python.terminal.activateEnvironment": true
   }

5. Open VS Code in the folder: code . (from PowerShell in root).
6. Status bar shows "Select Interpreter" triangle. Command Palette > "Python: Select Interpreter" > Enter absolute path Z:\0400 Dokumentation\0001 IT Dokumentation\0001 Skripte\PY_Test_with_GROK\.venv\Scripts\python.exe – selects successfully, status bar updates to correct path.
7. Create src/main.py with sample code (e.g., import requests; response = requests.get('https://api.github.com'); print(response.status_code)).
8. Press F5 on main.py: Debugger starts, but logs show warnings/errors.

Expected Behavior

• Venv auto-detected from relative path in settings.json.
• No scan errors; status bar updates automatically.
• F5 debugs using venv interpreter without manual selection or launch.json tweaks.
• Terminal auto-activates venv with (.venv) prefix.

Actual Behavior

• "Select Interpreter" triangle persists until manual absolute path selection.
• Logs (Output > Python) show repeated warnings:

  [warning] Identifier for virt-virtualenv failed to identify .venv\Scripts\python.exe [Error: ENOENT: no such file or directory, scandir 'C:\Users\tuzi\AppData\Local\Programs\Microsoft VS Code\.venv\Scripts'] {
    errno: -4058,
    code: 'ENOENT',
    syscall: 'scandir',
    path: 'C:\\Users\\tuzi\\AppData\\Local\\Programs\\Microsoft VS Code\\.venv\\Scripts'
  }
  

  (Extension scans wrong AppData path instead of Z:\ project.)
• Additional warning: Dir "z:\0400 Dokumentation\0001 IT Dokumentation\0001 Skripte\PY_Test_with_GROK\.pixi\envs" is not watchable (directory does not exist) – scans for non-existent Pixi envs.
• F5 prompts "Select Debugger" loop: "Python Debugger" > "Python File" > "create a launch.json file" > Loops back to config menu.
• Manual launch.json creation in .vscode with absolute "python" path fixes F5, but relative paths fail.
• Terminal activates venv manually, but auto-activation inconsistent.

Logs (from Output > Python, after Reload Window)

2025-10-13 01:56:43.567 [warning] Identifier for virt-virtualenv failed to identify .venv\Scripts\python.exe [Error: ENOENT: no such file or directory, scandir 'C:\Users\tuzi\AppData\Local\Programs\Microsoft VS Code\.venv\Scripts'] {
  errno: -4058,
  code: 'ENOENT',
  syscall: 'scandir',
  path: 'C:\\Users\\tuzi\\AppData\\Local\\Programs\\Microsoft VS Code\\.venv\\Scripts'
}
2025-10-13 01:56:43.908 [info] Finished searching for windows registry interpreters: 589 milliseconds
2025-10-13 01:56:43.910 [info] Environments refresh paths discovered (event): 591 milliseconds
2025-10-13 01:56:43.910 [info] Environments refresh paths discovered: 591 milliseconds
2025-10-13 01:56:43.958 [info] Environments refresh finished (event): 639 milliseconds
2025-10-13 01:56:43.965 [info] Environment refresh took 647 milliseconds
2025-10-13 01:56:52.885 [info] Active interpreter [z:\0400 Dokumentation\0001 IT Dokumentation\0001 Skripte\PY_Test_with_GROK]:  Z:\0400 Dokumentation\0001 IT Dokumentation\0001 Skripte\PY_Test_with_GROK\.venv\Scripts\python.exe
2025-10-13 01:56:52.909 [info] Python interpreter path: .\.venv\Scripts\python.exe
2025-10-13 01:56:52.910 [info] Discover tests for workspace name: PY_Test_with_GROK - uri: z:\0400 Dokumentation\0001 IT D

2025-10-13 02:14:57.902 [info] Telemetry level is off
2025-10-13 02:14:57.902 [info] Experiments are disabled, only manually opted experiments are active.
2025-10-13 02:14:57.902 [warning] Dir "z:\0400 Dokumentation\0001 IT Dokumentation\0001 Skripte\PY_Test_with_GROK\.pixi\envs" is not watchable (directory does not exist)
2025-10-13 02:14:58.110 [info] Python interpreter path: .\.venv\Scripts\python.exe
2025-10-13 02:14:58.141 [info] > pyenv which python
2025-10-13 02:14:58.141 [info] cwd: z:\0400 Dokumentation\0001 IT Dokumentation\0001 Skripte\PY_Test_with_GROK
2025-10-13 02:15:02.724 [info] Starting Pylance language server.

Additional Notes

• Manual absolute path in settings.json and launch.json works as workaround, but relative paths (./.venv) fail on SMB.
• Similar to My file wrongly autodetected as Javascript instead of Javascript React vscode#24525 (poetry on X:\ with .pixi\envs ENOENT), but reproducible with plain venv – may be dupe or extension.

Greetings

Don Jayamanne (@DonJayamanne)
Brett Cannon (@brettcannon)

VS Code version: Code 1.105.0 (03c265b1adee71ac88f833e065f7bb956b60550a, 2025-10-08T14:09:35.891Z)
OS version: Windows_NT x64 10.0.26100
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