vscode-python: Debugging test in VS Code does not work

@asipras Can you add the following configuration to your launch.json:

        {
            "name": "Python: Test debug config",
            "type": "python",
            "request": "test",
            "console": "integratedTerminal",
            "logToFile": true
        }

Try debugging your tests, and copy here the content of the debugpy*.log file from the extension folder.

@lorenzo-cavazzi are you getting the same Duplicate entries in "env" message? If that’s the case, there is something else going on in your setup that’s not related to the extension, because it’s a Windows-specific error message from the debugger:

https://github.com/microsoft/debugpy/blob/69db68a5f9aff6c1dfd955c8934c753212f94633/src/debugpy/launcher/handlers.py#L110-L119

@shaperilio Same issue here. I was able to fix by adding the following to launch.json per instructions from a few years ago in thread above:

    {
        "name": "Python: Test debug config",
        "type": "python",
        "request": "test",
        "console": "integratedTerminal",
        "logToFile": true
    }

I just ignored the linting error on “request” type.

Same - downgrade Python extension to v2023. 4.1 solved the issue.

Not sure why this issue is just sitting here, but it’s come up again. When I try to debug a test with the Python Extension version v2023.6.0, I get "Invalid message: Found duplicate in "env": PATH

Version 2023.4.1 works just fine.

The error message is not helpful; it certainly makes it seem like I should know what to do with launch.json.

I tried to turn on logging as suggested above, but I can’t find the log file… no idea if that setting is still valid.

@robinstauntoncollins I can confirm this launch config is working.

Unfortunately then VS Code complains “test” isn’t a valid value for request. Valid values are “launch” or “attach”. Is there any solution/workaround for this?

I am facing the same issue.

@robinstauntoncollins I can confirm this launch config is working.

Unfortunately then VS Code complains “test” isn’t a valid value for request. Valid values are “launch” or “attach”. Is there any solution/workaround for this?

Same issue here, no longer possible to debug my python tests suite after updating to v2023.6.0. None of the configuration metioned above solve the problem for me.

Back to work after downgrading to v2023.4.1

This seems to be fixed in the pre-release version (I’m on v2023.7.11011538)

I found out, that in my case the duplicate entries error occures when I launch VS Code vie terminal using Git Bash.

When I launch it by desktop shortcut everything works fine.

this might help someone, here is part of lanuch.json which finally worked with pytest

{
            "name": "PyTest",
            "type": "python",
            "request": "test",
            "stopOnEntry": false,
            "module": "pytest",
            "console": "integratedTerminal",
            "logToFile": true,
            "args": [
                "-v",
            ],
            "cwd": "${fileDirname}",
            "env": {
                "PYTEST_ADDOPTS": "--no-cov"
            },
        },

if using pytest and coverage, debugger won’t break – so py-cov needs deactivating

also, request needs to be test (even if vscode complains about it being invalid)

@lhotamir Same for me. Launching using code . from Git Bash terminal results in this error when trying to test: Invalid message: Found duplicate in “env”: PATH.

Launching using Windows shortcut or adding:

        {
            "name": "Python: Test debug config",
            "type": "python",
            "request": "test",
            "console": "integratedTerminal",
            "logToFile": true
        }

to launch.json resolves the problem.

Amazing that this problem still exists nearly two years later.

Just in case someone is having the same problems I was having and can’t get this to work at all but needs it to, this is how i get it to work for me. I actually modify the handlers.py file located at

%HOMEPATH%\.vscode\extensions\ms-python.python-xxx.x.xxxx\pythonFiles\lib\python\debugpy\launcher\handlers.py

I comment out the lines that checks for duplicate entries:

Around line 89 you will see:

 env_change = { k.upper(): v for k, v in env_changes.items() }

Comment this line out:

 # env_change = { k.upper(): v for k, v in env_changes.items() }

I have to do this when I restart code, but this allows me to do debugging.

        {
            "name": "Python: Test debug config",
            "type": "python",
            "request": "test",
            "console": "integratedTerminal",
            "logToFile": true
        }

@kimadeline I did what you suggested. Below is my launch.json. What is amazing is now I can debug test using latest version of python extension 2020.03.69010. If I remove the configuration that you suggested from my launch,json then I get the same error.

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Python: Current File",
            "type": "python",
            "request": "launch",
            "program": "${file}",
            "console": "integratedTerminal"
        },
        {
            "name": "Python: Test debug config",
            "type": "python",
            "request": "test",
            "console": "integratedTerminal",
            "logToFile": true
        }
    ]
}

debugpy.adapter-27144.log debugpy.launcher-29020.log debugpy.pydevd.24988.log debugpy.server-24988.log

To me this issue does not seem to be fixed. I am currently running v2023.22.1 of the plugin together with behave.

Error message is exaclty the same one as reported initially.

When I downgrade to 2023.8.0 it will work again.

The following did not help:

"python.experiments.optInto": ["pythonTestAdapter"]

For me I’m using unittest not Pytest but by changing the settings.json to this fixed it for me:

{ “python.testing.unittestArgs”: [ “-v”, “-s”, “${workspaceFolder}/”, “-p”, “test.py” ], “python.testing.pytestEnabled”: false, “python.testing.unittestEnabled”: true }

The equivalent configuration to the deprecated way above looks like:

launch.json

    {
      "name": "Python: Test debug config",
      "type": "python",
      "request": "launch",
      "console": "integratedTerminal",
      "purpose": ["debug-test"],
      "logToFile": true
    }

See this debug recommendation…

https://github.com/microsoft/vscode-python/blob/5528e0efb9b8c91c83dfb356391085280fb63417/src/client/debugger/extension/configuration/debugConfigurationService.ts#L75

For some reason this problem repeated in version 2023.3.10411009. In my case Path is simply PATH twice, PYTHONPATH also just duplicate of itself.

Still the same issue here. It feels very frustrating cause the debug functionality is used by everyone at my company and we always need to downgrade the extension to the 8.1 version.

Hello @asipras and @lorenzo-cavazzi, thank you for reaching out.

Can I ask you both to provide the following:

• A sample repo (just the .vscode/settings.json is sadly not enough for me to replicate this issue, I can debug tests correctly);
• The content of the Python output panel (View→Output, change the drop-down the upper-right of the Output panel to Python).

Can you also confirm that if you downgrade to the previous release of the extension (2020.2.64397) you can debug tests correctly:

@lorenzo-cavazzi what do you mean by that:

For some reason, trying to install a different version of the Python extension doesn’t work.

Thanks!