The class Symfony\Component\ClassLoader\ApcClassLoader is declared but never used. You should remove the use statement.
<?php
use Symfony\Component\ClassLoader\ApcClassLoader;
use Symfony\Component\HttpFoundation\Request;
$loader = require_once __DIR__.'/../app/bootstrap.php.cache';
// Use APC for autoloading to improve performance.
in web/app.php, line 3
Posted from SensioLabsInsight