Debugger doesn't follow the trace well and make it very hard debug

I have the Pycharm Professional and often got this problem:


When I trace the logic in debugger, sometimes at a step, the tracer doesn't stop at the source line it should be, and therefore makes it hard to understand the logic. The attached screenshot is a good example to show the problem. Please read it and hopefully let me know it's a known issue and has a solution to it. It's very important.

As you can see from the screenshot, the 'variable

en_start_index_found = False

But the tracer stops at the inside of the condition check:

if en_start_index_found:

' How can this happen? Such things make me hard to follow the logic. This doesn't happen all the time but it indeed happens sometimes.

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I suspect it's related to this issue:

Could you try to add PYDEVD_USE_CYTHON=NO env variable to your run/debug configuration as mentioned here: ?

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Thanks for the info, but my code does use cython, so I can't disable it. Is this issue being actively worked?

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>my code does use cython

This is irrelevant AFAIK, we disable cython speedups only for debugger in this case.

Please add the env variable according to and let me know if it helps.

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I'm running into this problem also. (I'm up-to-date with Build #PY-193.6911.25, built on March 18, 2020).  The PYDEVD_USE_CYTHON=NO setting seems to fix it. (And after a couple more days, it definitely does seem to have worked.)


It may be coincidence, but I did not notice the issue prior to installing the latest update.



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