Why did the mysql client, when communicating with Sphinx through an ssh tunnel, start giving the error "ERROR 2000 (HY000): Unknown MySQL error"?

Question

MySQL

After upgrading Ubuntu to 20.04 from 18.04 there was some subj nonsense.
The connection goes through an ssh tunnel. If you disable it, then the client swears at the lack of communication, from which I make the assumption that the problem is not in ssh.

# mysql --version
mysql  Ver 8.0.23-0ubuntu0.20.04.1 for Linux on x86_64 ((Ubuntu))

Where the Sphinx is

# searchd -foo
Sphinx 2.2.11-id64-release (95ae9a6)

In the same place, you can connect to it with the following client:

# mysql --version
mysql  Ver 15.1 Distrib 10.3.23-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2

Or at least how it can be debugged.
I did not find any mysql client error logs, it seems that they are nowhere to be found.

UPD: Will Sphinx work with mysql-client version 8 at all?

Answer 1

UPD: Will Sphinx work with mysql-client version 8 at all?

you are amazingly quick-witted ...
in general, 5.7 was changed to 8 (and not 6.0) for a reason, and for a reason they live in parallel,
add to this the problems of the sphinx with official clients downloaded from mysql.com on Windows and conclude that you no one promised anything
outputs
1) connector in required language that works
2) client from 5 mysql
3) sphinx 3 version
4) manticoresearch