Symfony Update 2.8 to 3.4
I wanted to upgrade my old Symfony project from 2.8 to 4.0 but I stacked at upgrade from 2.8 to 3.4. I used this tutorial for the upgrade Moving to Symfony 3.4 . I got some errors while trying to update through composer Composer Upgrade Errors : # php composer.phar update symfony/symfony --with-dependencies Dependency "symfony/polyfill-apcu" is also a root requirement, but is not explicitly whitelisted. Ignoring. Dependency "twig/twig" is also a root requirement, but is not explicitly whitelisted. Ignoring. Dependency "ircmaxell/password-compat" is also a root requirement, but is not