Comment 3 for bug 1902023

Thank you for taking the time to file a bug report.

Checking your logs the only relevant information we have is this:

update-alternatives: error: alternative path /etc/mysql/mysql.cnf doesn't exist

Which means the config file is missing for some reason (this file is shipped in mysql-server-8.0). I can see you installed mariadb and then installed mysql on top of it, and then tried to remove it multiple times without success. I'd like to make it clear that a co-installation of mariadb and mysql is not supported. Moreover, I am wondering which manual interventions you made among all those attempts of removing it. Please, provide all the steps that led you to this inconsistent state.

Since it seems likely to me that this is a local configuration problem,
rather than a bug in Ubuntu, I am marking this bug as 'Incomplete'.

However, if you believe that this is really a bug in Ubuntu, then we would
be grateful if you would provide a more complete description of the problem
with steps to reproduce, explain why you believe this is a bug in Ubuntu
rather than a problem specific to your system, and then change the bug
status back to "New".

For local configuration issues, you can find assistance here:
http://www.ubuntu.com/support/community