Unable to debug in pycharm with pytest

For my situation, I found what the problem is:

If there is --cov in pytest.ini, then breakpoints in pycharm won't work, after deleting all --cov in pytest.ini, the breakpoints in pycharm can work.

Reason:

"The coverage module and pycharm's debugger use the same tracing api (sys.settrace) - they don't work together. " -- https://github.com/pytest-dev/pytest-cov/issues/131

References:

How to debug py.test in PyCharm when coverage is enabled

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The root issue is debugging does not work if you have coverage enabled by default (usually on pytest.ini).

To disable just on pycharm, just add --no-cov on the Additional Arguments on the Run/Debug Configurations.
Update Templates -> Python tests -> pytest, so every new test gets this configuration.
After this, delete your current debug settings and redebug it.

https://i.stack.imgur.com/DmgRr.png

Pycharm 2018.3.x (still works in 2020.x)

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TL;DR: Disable the "Gevent compatible" flag in the "Build, execution, Deployment" -> "Python Debugger".

It seems that at some point I enabled the "Gevent compatible" debugger in pycharm, and since then pytest-pycharm stopped working. Disabling it will make pytest-pycharm work again. I hope this will solve the issue for some of you.

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I know that you had it right, but for me actually setting the Default test runner to pytest solved the problem. In PyCharm: Settings -> Python Integrated Tools -> Testing section -> Default test runner -> choose pytest from the dropdown menu -> Apply. And it instantly works.

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None of the solutions mentioned here or elsewhere worked for me.

I have multiple copies of the same project in different folders. Some copies were fine, others exhibited the following behavior:

debugger would ignore any breakpoints in tests (regardless if these were run as single functions, classes, modules, batches)

breakpoints set in actual code called by these tests were hit

What did work for me (4 broken repos and counting):

Delete contents of __pycache__ folders in your project, starting out from the directory where your undebuggable test module is located. Remove the .pyc file with the name of the undebuggable module first. If this doesn't help, identify any own imports used in the test, locate and delete the __pycache__/.pyc for them as well. (Note: use a file browsing tool like File Explorer because Pycharm doesn't show these directories in the project view.)

If you're still out of luck or just plain lazy (like me), wipe all the __pycache__ folders you have in your repo. You can do this via your command line/terminal, just navigate yourself to the repo folder and then:

find . -name __pycache__ -type d -exec rm -rf {} \; [linux, mac] (see How to remove folders with a certain name)

FOR /d /r . %d IN ("__pycache__") DO @IF EXIST "%d" rd /s /q "%d" [win] (see Batch command to delete all subfolders with a specific name)

EDIT: Made the description a bit detailed after recent findings, added a quick wipe hint. Noticed afterwards that @mcsj120 already suggested this in Antonin's post, so kudos to him!

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I'd like to add to this conversation that these fixes does not seem to work in the case a single test function is launched in PyCharm (rather than the whole test file).

I yet haven't found a solution online to activate breakpoints when debugging a single test function instead of the whole file, and if someone has a solution, I would be interested. If I find it myself, I'll try to update this post.

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For me the solution was to just create empty pytest.ini file in the test folder. After doing this I can also launch debug for specific functions.

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