I am trying to use the Symfony 4 demo application https://github.com/symfony/demo but when I install it with composer I get the error described below. I am using Ubuntu 16.04 and php 7.1 installed ...

I use AWS Cloud9 Amazon Web Services a.k.a. Cloud9 IDE. I’m trying to achieve a setup where I can easily switch the frontend (not CLI) PHP version with PHPBrew between 5.6 and 7 whenever. For now, ...