On checking error log of /var/log/mysql/error.log, I see this:
160628 11:50:37 [ERROR] /usr/sbin/mysqld: unknown option '--safe-show-database'
160628 11:50:37 [ERROR] Aborting
I solved this by commenting out a few lines for safe mode in /etc/mysql/my.cnf
$sudo vi /etc/mysql/my.cnf
[mysqld_safe]
socket = /var/run/mysqld/mysqld.sock
nice = 0