title: Enabling Symfony's AppCache replaces Doctrine's ApcCache
body: <p>When enabling <code>AppCache</code> in my Symfony application, suddenly any injected <code>ApcCache</code> gets replaced with <code>AppCache</code> instances, yielding:</p>
  
  <blockquote>
    <p>Argument passed to MyClass::__construct() must be an instance of Doctrine\Common\Cache\ApcCache, instance of AppCache given</p>
  </blockquote>
  
  <p>The injection happens through:</p>
  
  <pre><code>services:
      my_class:
          class: MyClass
          arguments:
              - @cache
      cache:
          class: Doctrine\Common\Cache\ApcCache
  </code></pre>
  
  <p>Which seems very weird. Any suggestions on how to fix this would be much appreciated.</p>