Debugger doesn't stop at breakpoints with pytest if pytest-cov is used

[lmazuel]

Environment data

VS Code version: 1.19.3
Python Extension version: 2018.1.0
Python Version: 3.6.2
OS and version: Windows 10 latest update

Actual behavior

My initial setup has this setup.cfg file:

[tool:pytest]
addopts = --cov=mymodulename

This adds automatically a "--cov" to every "pytest" call, but prevents VSCode to stop at breakpoints. If I remove the file (or at least the --cov), I get back my breakpoints stop.
I changed my setup to put that in my Travis file instead, but I feel like this should work :/

Expected behavior

I should be able to have this file (and coverage) and debug at the same time.

Steps to reproduce:

• Install pytest and pytest-cov
• Create a setup.cfg as describe before
• Create even a simple test with a breakpoint inside

[lmazuel]

Note that the test is executed correctly. Even the "run test"/"debug test" button on each test executes correctly this individual test.

[DonJayamanne]

@lmazuel apologies for the delay.
Looks like its not possible to debug the code with coverage enabled (http://pytest-cov.readthedocs.io/en/latest/debuggers.html).
I guess we'll have to disable 'coverage' on the fly when debugging (using the flag "--no-cov").

[DonJayamanne]

Hmm, looks like we're not the only ones having trouble with debugging + pytest + coverage (https://www.jetbrains.com/help/pycharm/run-debug-configuration-py-test.html)

I've tried passing in the flag --no-cov, but that causes pytest to fall over of pytest-cov isnt installed.

I guess we could try to determine if Pytest-cov is installed or not.

[DonJayamanne]

@lmazuel
Unfortunately we're not going to be able to resolve this easily, hence we're closing this.
My suggestion is to modify the pytest args in the settings.json to manually pass in the --no-cov flag to enable debugging.
I understand this isn't the best solution, as you'll be modifying the settings on and off.