ipdb: RuntimeWarning: 'ipdb.__main__' found in sys.modules after import of package 'ipdb'

Question

I am using ipdb to debug my python like below:

python -m ipdb my_test.py -d my_input_config -o my_output

and got the following errors:

/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/runpy.py:125: RuntimeWarning: 'ipdb.__main__' found in sys.modules after import of package 'ipdb', but prior to execution of 'ipdb.__main__'; this may result in unpredictable behaviour
  warn(RuntimeWarning(msg))

What does this mean and how do I fix this? Thank you!

Wadi

see here – Pacific

https://mcmap.net/q/367954/-python-multiprocessing-error-attributeerror-module-39-__main__-39-has-no-attribute-39-__spec__-39 This might be useful – Inigo

Typing __spec__ = None as soon as ipdb starts up seems to solve the "unpredictable" behavior (like the link above says) but it'd be nice to know why this happens and how to solve it without that workaround. – Monolatry