I'm afraid this is leaving the realm of a bug report and entering one of
support.
The upgrade path in the code can be seen in /var/lib/dpkg/info/mysql-
server-5.7.postinst:
start_server "$mysql_statedir" "$tmpdir" "skip_grant" || result=$?
# If the server fails to start, then skip the
I'm seeing errors like these in your logs:
2019-02-22T22:01:48.488648Z 0 [ERROR] InnoDB: Unable to lock ./ibdata1 error: 11
2019-02-22T22:01:48.488703Z 0 [Note] InnoDB: Check that you do not already have
another mysqld process using the same InnoDB data or log files.
Maybe you have a stale mysql
