MySQL: How to ignore /etc/mysql/my.cnf for mysqld --initialize I compile a 5.7 MySQL database from source into a custom directory and use mysqld --initialize to initialize the database.

This works fine as long as there is no MySQL installed on the main system, or when I use mv /etc/mysql/my.cnf /etc/mysql/my.cnf_backup to get rid of the system-wide file, but of course that is a terrible workaround that breaks the system-wide mysql installation.

If a /etc/mysql/my.cnf is present, the initialization fails obviously as the paths are all wrong.

mysqld --initialize always seems to prefer /etc/mysql/my.cnf and ignores any file I specify on the command line with --defaults-file. It does however use single parameters that are specified on the command line (so it may work if I translate my complete my.cnf file into command line arguments, but that again is not a good solution and creates other problems)

Of course the whole point why I build from source into a custom directory is because I want it independent from any things that are installed on the main system.

Is there a way to let mysqld --initialize ignore /etc/mysql/my.cnf?
The manual mentions that the --defaults-file option has to be specified first, if you want to use it.
Otherwise the option is ignored.