title: Android Build Error: Attribute Signature requires InnerClasses attribute. Check -keepattributes directive
body: <p>I'm facing this error when trying to build the app in release mode. </p>
  
  <blockquote>
    <p>Error: Attribute Signature requires InnerClasses attribute. Check -keepattributes directive</p>
  </blockquote>
  
  <p>My <code>proguard-rules.pro</code> line looks like this:</p>
  
  <pre><code>-keepattributes Signature
  </code></pre>
  
  <p>what InnerClasses is the compiler referring to? What am I omitting?</p>