title: Symfony2 cache clear bad with sh
body: <p>clearing symfony2 cache on shared server with:</p>
  
  <pre><code>php app/console cache:clear --env=prod
  </code></pre>
  
  <p>Gives me red box with error:</p>
  
  <pre><code>[RuntimeException]
  sh:  :  command not found
  </code></pre>
  
  <p>It used to work before on the server, not sure what changed and how to correct this?</p>