Thanks for reporting this! I mysql-5.5/5.6 the mysql_plugin is part of the client package: mysql-client-5.6.install:usr/bin/mysql_plugin mysql-client-5.6.manpages:debian/tmp/usr/share/man/man1/mysql_plugin.1
In MariaDB it is part of server package: mariadb-server-10.0.install:usr/bin/mysql_plugin mariadb-server-10.0.manpages:debian/tmp/usr/share/man/man1/mysql_plugin.1 As this command controls what plugins the server loads, I think the proper location indeed is in the server package (as upstream did) and I will not change it, instead I added breaks/replaces to overwrite file ( https://www.debian.org/doc/debian-policy/ch-relationships.html#s7.6.1) in commit http://anonscm.debian.org/cgit/pkg-mysql/mariadb-10.0.git/commit/?id=7bda76751754145a66239c8f9fd343d47fd1c1b0 This fix will be uploaded once 10.0.15 it is finalized for Debian.
