A metapackage to enforce a lowest version on installed Symfony components
This metapackage conflicts with lower versions of standalone Symfony packages. This effectively means that it prevents Composer from installing lower versions you'd like to exclude. It is expected to be used only in root packages, and not by library authors. Open-source authors might still find it usefull to test several versions of Symfony components in their C.I.
Use the Composer command line:
composer require symfony/force-lowest v4.1
Replace the version number by the lowest one you'd like for Symfony packages.