title: Symfony2 app/console --env throws no envirorment name
body: <p>I'm working with symfony2 and while migrating from Beta2 version to the current one I messed up with some environment configuration.</p>
  
  <p>My trouble here is when I run</p>
  
  <pre><code>php app/console --env
  </code></pre>
  
  <p>I get the following error</p>
  
  <pre><code>[InvalidArgumentException]
  The file "MyWebRoute\symfony-standard\app/config/config_.yml" does not exist.
  </code></pre>
  
  <p>How should I get this working?
  What should the proper configuration be?</p>