I'm new using symfony, and I have to use symfony 4 AND fos user bundle but I can't install it using composer ( since it's not officially supported ) , and I'm wondering how to bypass this. Can you explain me how to do it ?
FOSUserBundle is now compatible with Symfony 4 from release 2.1.0 (https://github.com/FriendsOfSymfony/FOSUserBundle/releases/tag/v2.1.0)
You can install FOSUserBundle with simple composer command :
composer require friendsofsymfony/user-bundle "~2.0"
The documentation is not, at this moment, very clear about how to install this bundle with Symfony 4. I have write a How To here