I am not sure, but i think this is related with code,
in my code, use Symfony by
when i run the process it show error of time out.
but this seems related to code
on constructor there is a var cal $timeout
public function __construct($commandline, $cwd = null, array $env = null, $input = null, $timeout = 60, array $options = array())
So when you initial the class
$process = new Process($command, null, null,null, 300);
here 300 in the timeout limit.
Note : for my case this work, but your case be different