mysqldb crashes or otherwise misbehaves on python 3.8.0b1 if warnings as errors are enabled

[zzzeek]

I'm getting lots of different varieties of this failure but the general idea seems to be that if deprecation warnings raise errors, MySQLdb can't run queries, Python 3.8.0b1:

import warnings
import MySQLdb

# remove this to eliminate errors
warnings.filterwarnings("error", category=DeprecationWarning)


conn = MySQLdb.connect(user="scott", password="tiger", host="localhost", db="test")
cursor = conn.cursor()
cursor.execute("select 1")

output:

Traceback (most recent call last):
  File "test3.py", line 9, in <module>
    cursor.execute("select 1")
  File "/home/classic/dev/sqlalchemy/.tox/py38-mysql/lib/python3.8/site-packages/MySQLdb/cursors.py", line 206, in execute
    res = self._query(query)
  File "/home/classic/dev/sqlalchemy/.tox/py38-mysql/lib/python3.8/site-packages/MySQLdb/cursors.py", line 312, in _query
    db.query(q)
  File "/home/classic/dev/sqlalchemy/.tox/py38-mysql/lib/python3.8/site-packages/MySQLdb/connections.py", line 224, in query
    _mysql.connection.query(self, query)
MySQLdb._exceptions.ProgrammingError: (1064, <NULL>)

If I try to use charset, I get something different (likely because it is tripping over a deprecation warning -> error somewhere else):

import warnings
import MySQLdb

warnings.filterwarnings("error", category=DeprecationWarning)


conn = MySQLdb.connect(user="scott", password="tiger", host="localhost", db="test", charset="utf8mb4")
cursor = conn.cursor()
cursor.execute("select 1")

raises:

MySQLdb._exceptions.ProgrammingError: (1064, 'You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near \'H??t\'H??t"1?f\x0f\x1f?\' at line 1')

but what's weird is that it's not raising for a deprecation warning, so it looks like something is happening in the C code

[zzzeek]

similar issue observed in cx_Oracle at oracle/python-cx_Oracle#317