The debugging session fails silently immediately after clicking 'Start Debugging' (On Windows only)

[rene-deltares]

At some point last year, debugging python code in vscode stopped working on my work laptop (running Windows 10). The problem only occurs when I open a folder/workspace in Windows. I mostly work in Linux in VSCode through the WSL remote connection. When connected through WSL, the debugging extension works without problems. I mostly work through WSL, so I ignored the problems I had on Windows. Now, months later, we're experiencing a crash in our Python code that only occurs on Windows. Not being able to run with debugging in Windows VSCode is making it really hard to help out my colleages.

So far I tried reviewing my launch.json and settings.json, updating the extension to the latest version and the latest pre-release version, and checking the 'Python Debugger' output pane.

The problem

I created a few configurations in my launch.json. Some for specific python programs, and one for the pytest test suite. If I click 'Start debugging', nothing much seems to happen:

• A 'loading bar' and the tiny 'debug' menu (with the continue, step, stop and pause buttons) flash on the screen for a fraction of a second, then disappear.
• The 'Python Debugger' output shows two new lines:
  • Resolving launch configuration with substituted variables
  • DAP Server launched with command: <my-repo-dir>\.venv\Scripts\python <home-dir>\.vscode\extensions\ms-python.debugpy-2024.15.2024121701-win32-x64\bundled\libs\debugpy\adapter

I configured the test discovery in vscode, and I can run our test suite just fine. But when I click 'Debug test' on any test, the test doesn't run. The spinner seems to run indefinitely. I get the same two lines as above in the 'Python Debugger' output.

I should mention that I have been able to debug with python just fine in the past, and not much has changed in my configuration since (if anything, I don't know if the problem occurred because of a settings change). As far as I can tell I'm using a bogstandard vscode configuration for a simple python project.

Using the logToFile option in launch.json

The only progress I made is to add "logToFile": true to my debug configuration in launch.json. I can tell from the Python Debugger output that the extension is invoking a python program called adapter with an option to write a log file to my home directory (where my vscode extensions are stored). It didn't help me much, but maybe it can be of some help to you, so I'll attach the logfile to this issue.

debugger.vscode_uuid.log

Is there any way to see more verbose output than this? Or is there some other log I could check? I'm kind of stumped at this point, and I could use your help.

My configuration

VSCode:
Version: 1.96.2 (user setup)
Commit: fabdb6a30b49f79a7aba0f2ad9df9b399473380f
Date: 2024-12-19T10:22:47.216Z
Electron: 32.2.6
ElectronBuildId: 10629634
Chromium: 128.0.6613.186
Node.js: 20.18.1
V8: 12.8.374.38-electron.0
OS: Windows_NT x64 10.0.19045

VSCode extensions:
ms-python.python: 2024.22.2
ms-python.debugpy: 2024.15.2024121701

Python: 3.12.0

launch.json:

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Debug my-program",
            "type": "debugpy",
            "request": "launch",
            "program": "${workspaceFolder}\\my-program.py",
            "logToFile": true,
            "args": [
                "--flag",
                "--with=argument"
            ],
            "console": "integratedTerminal",
            "justMyCode": false
        },
        // ...
    ]
}

settings.json

{
    "python.defaultInterpreterPath": "${workspaceFolder}\\.venv\\Scripts\\python.exe",
    "python.terminal.activateEnvironment": true,
    "python.testing.pytestEnabled": true,
    "python.testing.autoTestDiscoverOnSaveEnabled": true,
    "python.envFile": "${workspaceFolder}\\.env",
    // ...
}

Thanks!