base64.b32decode() function leads into "UnboundLocalError: local variable 'acc' referenced before assignment" when passing 8 equality signs as data:

>>> import base64
>>> base64.b32decode(b"========")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/tmp/python-3.7-bin/lib/python3.7/base64.py", line 235, in b32decode
    acc <<= 5 * padchars
UnboundLocalError: local variable 'acc' referenced before assignment

When passing a different number of equality signs, the documented binascii.Error exception is thrown.