Hallo
Probably better depend on one of the following virtual packages instead
of adding mariadb-server-core-5.5:
chammers@sys-251:~$ apt-cache search virtual-mysql-server-core
mariadb-server-core-10.0 - MariaDB database core server files
mysql-server-core-5.5 - MySQL database server binaries
chammers@sys-251:~$ apt-cache search virtual-mysql-server
mariadb-server-10.0 - MariaDB database server binaries
mariadb-server-core-10.0 - MariaDB database core server files
mysql-server-5.5 - MySQL database server binaries and system database setup
mysql-server-core-5.5 - MySQL database server binaries
tschüss,
-christian-