title: How to debug with obfuscated (with ProGuard) applications on Android?
body: <p>When I got something like this</p>
  
  <pre><code>ERROR/AndroidRuntime(18677): Caused by: java.lang.NullPointerException
  ERROR/AndroidRuntime(18677):     at com.companyname.a.a.a(Unknown Source)
  </code></pre>
  
  <p>How can I know where the problem is and debug this issue?
  I only got the mapping output from ProGuard and don't know the line number.
  Thanks.</p>