Deprecation warnings are raised due to invalid escape sequences in Python 3.8 . Below is a log of the warnings raised during compiling all the python files. Using raw strings or escaping them will fix this issue.
find . -iname '*.py' | xargs -P 4 -I{} python -Wall -m py_compile {}
./webpack_loader/config.py:17: DeprecationWarning: invalid escape sequence \.
'IGNORE': ['.+\.hot-update.js', '.+\.map'],
./webpack_loader/config.py:17: DeprecationWarning: invalid escape sequence \.
'IGNORE': ['.+\.hot-update.js', '.+\.map'],