My overall upgrade went well, but I am left with a critically lingering issue of mysql-server not being able to install itself, and nothing I am trying gets it to work.
This is the error I see when trying to install/reinstall it:
Setting up mysql-server-5.7 (5.7.11-0ubuntu6) ... Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details. invoke-rc.d: initscript mysql, action "start" failed. dpkg: error processing package mysql-server-5.7 (--configure): subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of mysql-server: mysql-server depends on mysql-server-5.7; however: Package mysql-server-5.7 is not configured yet. dpkg: error processing package mysql-server (--configure): dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure. Processing triggers for systemd (229-4ubuntu4) ... Processing triggers for ureadahead (0.100.0-19) ... Errors were encountered while processing: mysql-server-5.7 mysql-server E: Sub-process /usr/bin/dpkg returned an error code (1)
I've tried completely removing it, though doing so attempts to install MariaDB because of dependencies (?). Any suggestions on what I can do to fix this would be most welcome.
EDIT: Looks like I'm not the only one: https://bugs.launchpad.net/ubuntu/+source/mysql-5.7/+bug/1573279