title: Firefox mobile Add-on SDK error message missing
body: <p>I'm using creating extension for mobile firefox using Addon SDK (1.17). I have a problem with displaying error messages in console.</p>
  
  <p>To load extension I use this command:
  <code>cfx run -a fennec-on-device -b adb --mobile-app firefox --force-mobile</code></p>
  
  <p>For displaying messages use: <code>adb logcat | grep console</code></p>
  
  <p>The result looks like this:</p>
  
  <pre><code>I/Gecko   ( 3612): console.log: extension-name: *** extension loaded ***
  I/stdout  ( 3612): console.log: extension-name: *** extension loaded  ***
  I/Gecko   ( 3612): console.error: extension-name: 
  I/stdout  ( 3612): console.error: extension-name: 
  I/Gecko   ( 3612): console.log: extension-name: message text
  I/stdout  ( 3612): console.log: extension-name: message text
  </code></pre>
  
  <p>It is really annoying to find the bug.</p>
  
  <p>Does anybody know, what how to make error message appear?</p>
  
  <p>Thanks.</p>