title: How to display the 404 error page in Symfony2 dev environment
body: <p>I want to work on the 404 page from the dev environment. I customize 404 using this file : <strong>app/Resources/TwigBundle/views/Exception/error.html.twig</strong></p>
  
  <p>This prod url work correctly : <code>mysite.com/404</code></p>
  
  <p>But this one <code>mysite.com/app_dev.php/404</code> throw a NotFoundHttpException and give me the dev debug page.</p>
  
  <p>Is it possible to display the error page instead of debug page ?</p>
  
  <p><strong>UPDATE:</strong></p>
  
  <p>The official documentation has now a chapter about that : <a href="http://symfony.com/doc/current/cookbook/controller/error_pages.html#testing-error-pages" rel="nofollow noreferrer">Testing Error Pages during Development</a></p>