Comment 2 for bug 1826451

This is at least part of the problem.

etting up mysql-server-5.7 (5.7.11-0ubuntu6) ...^M
Installing new version of config file /etc/apparmor.d/usr.sbin.mysqld ...^M
Installing new version of config file /etc/init.d/mysql ...^M
Installing new version of config file /etc/init/mysql.conf ...^M
Installing new version of config file /etc/logrotate.d/mysql-server ...^M
Installing new version of config file /etc/mysql/debian-start ...^M
update-alternatives: using /etc/mysql/mysql.cnf to provide /etc/mysql/my.cnf (my.cnf) in auto mode^M
insserv: warning: script 'resolvconf' missing LSB tags and overrides^M
insserv: Default-Start undefined, assuming empty start runlevel(s) for script `resolvconf'^M
insserv: Default-Stop undefined, assuming empty stop runlevel(s) for script `resolvconf'^M
insserv: warning: script 'firstrun' missing LSB tags and overrides^M
mysql start/running, process 22749^M
mysql stop/waiting^M
mysql start/running, process 23042^M
mysql_upgrade: Got error: 1045: Access denied for user 'debian-sys-maint'@'localhost' (using password: YES) while connecting to the MySQL server^M
Upgrade process encountered error and will not continue.^M
mysql_upgrade failed with exit status 11^M
dpkg: error processing package mysql-server-5.7 (--configure):^M
 subprocess installed post-installation script returned error exit status 1^M
dpkg: dependency problems prevent configuration of mysql-server:^M
 mysql-server depends on mysql-server-5.7; however:^M
  Package mysql-server-5.7 is not configured yet.^M
^M
dpkg: error processing package mysql-server (--configure):^M
 dependency problems - leaving unconfigured^M