The file is indeed missing. It should've been in the mysql-server-core-5.6 package, but it's not.
In ruby-mysql2: Add --keep-my-cnf to the mysql_install_db command line. Since the server is started with --no-defaults, it's not going to read the my.cnf file, and mysql_install_db doesn't need to create it.
In mysql-server-core-5.6: Add usr/share/mysql/my-default.cnf to the package. mysql_install_db expects to find it.
The file is indeed missing. It should've been in the mysql-server- core-5. 6 package, but it's not.
In ruby-mysql2: Add --keep-my-cnf to the mysql_install_db command line. Since the server is started with --no-defaults, it's not going to read the my.cnf file, and mysql_install_db doesn't need to create it.
In mysql-server- core-5. 6: Add usr/share/ mysql/my- default. cnf to the package. mysql_install_db expects to find it.