Comment 3 for bug 1987068

Thank you for the bug report. From your logs I see that you installed mariadb-server and mariadb-client prior to installing mysql-server. Unfortunately the two applications are incompatible, and the failure was likely caused by that. If you would rather use mysql you can try to reinstall it by running the following commands:

sudo apt purge mysql* mariadb*
sudo apt install mysql-server

If this works please let me know