Running Pycharm debugger raise following exception: INFO:werkzeug: * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit) PYDEV DEBUGGER WARNING: sys.settrace() should not be used when the debugger is being used. This may cause the debugger to stop working correctly. If this is needed, please check: http://pydev.blogspot.com/2007/06/why-cant-pydev-debugger-work-with.html to see how to restore the debug tracing back correctly. Call Location: File "/.../venv/lib/python3.6/site-packages/coverage/collector.py", line 278, in _installation_trace sys.settrace(None) As the exception shows, there is a conflict between Pycharm debugger and coverage package. Here are my Pycharm execution configurations: How can I solve this issue? Continue reading...