title: How to set parameters or services in Symfony in PHPUnit tests?
body: <p>We are using PHPUnit to test parts of our application. In some tests, we want to change the value of a parameter or override a service (but only for that test, <em>not for all tests</em>).</p>
  
  <p><strong>What is the recommended way to configure Symfony's container on the fly in tests?</strong></p>
  
  <p>The problem we have met is that the container doesn't recompile itself when config is set on the fly (because it only recompiles itself when files have changed).</p>