title: Firebase Crashlytics custom log does not appear in the console
body: <p>I've been testing <code>Firebase Crashlytics</code> and even though the normal crash report works right I can't success trying to generate a custom as it says the <a href="https://firebase.google.com/docs/crashlytics/customize-crash-reports?authuser=0" rel="noreferrer">documentation</a>.</p>
  
  <pre><code>Crashlytics.log(msg); 
  </code></pre>
  
  <p>I also would like to know wether setting the user identifier for <code>Crashlytics</code> can be done for any crash (according to the doc I've understood that it's possible) with </p>
  
  <pre><code>void Crashlytics.setUserIdentifier(String identifier); 
  </code></pre>
  
  <p>and how it would have to be done, because it does neither work to me, I can't see anything on the <code>Firebase crashlytics console</code>.</p>
  
  <p>Thanks in advance!</p>