Plugin 'unix_socket' is not loaded after MariaDB replacement

[Jean-Baptiste Pressac]

Hello,
On Debian, I tried to replace MariaDB by MySQL 5.7 with command:

apt install mysql-server

But I am stuck to mysql_secure_installation with:

Error: Plugin 'unix_socket' is not loaded

I tried to add plugin-load-add=auth_socket.so to /etc/mysql/mysql.conf.d/mysqld.cnf but it does not solve my problem.

Thanks,