Bug when using mariadb v11.4 ?

[jgb]

Describe the bug

I have about a dozen pytests that work fine on mariadb v10.11.9 and earlier, but that break when upgrading to mariadb v11.4.
It concerns a traditional python / django web application, and the queries being executed a rather trivial (plain old SELECT with basic WHERE and LIMIT clauses).

On the application side, I see this traceback:

    def query(self, query):                                                                                                                                                                                                                    
        # Since _mysql releases GIL while querying, we need immutable buffer.                                                                                                                                                                  
        if isinstance(query, bytearray):                                                                                                                                                                                                       
            query = bytes(query)                                                                                                                                                                                                               
>       _mysql.connection.query(self, query)                                                                                                                                                                                                   
E       django.db.utils.OperationalError: (2013, 'Lost connection to MySQL server during query')                                                                                                                                               
                                                                                                                                                                                                                                               
/root/.venv/vidicenter/lib/python3.12/site-packages/MySQLdb/connections.py:261: OperationalError                

On the mariadb side, I see these in the error logs for each failed query:

2024-09-12 11:50:40 606 [Warning] Could not read packet: fd: 90  state: 1  read_length: 4  errno: 71  vio_errno: 1158  length: -1
2024-09-12 11:50:40 606 [Warning] Aborted connection 606 to db: 'test_vidicenter_gw1' user: 'root' host: '172.19.0.6' (Got an error reading communication packets)

I've tried to debug this from many angles, tried to find bug reports in any relevant libraries, but nothing turns up.
What I learned so far is that errno 71 means "protocol error".
Any idea what might be going on here?

Environment

MariaDB v11.4.3
Ubuntu 24.04 LTS
Python 3.12
Django v5.1.1
mysqlclient v2.2.4

How did you install libmysqlclient libraries?

apt install libmysqlclient-dev

What version of mysqlclient do you use?

2.2.4

Docker command to start MySQL server

No response

Minimum but complete code to reproduce

# Write Python code here.
import MySQLdb

conn = MySQLdb.connect(host='127.0.0.1', port=3306, user='root')
...

Schema and initial data required to reproduce.

-- Write SQL here.
-- e.g. CREATE TABLE ...

Commands, and any other step required to reproduce your issue.

No response

[jgb]

Nevermind, I found the problem.
Previously, I was using libmysqlclient-dev when building mysqlclient.
Up until mariadb v10.11.9 that worked fine, but as of v11.4.3 it seems I need libmariadb-dev instead.