title: Android Studio issue with R file
body: <p>I was using Android studio now for a long time and it was fine. Recently, not sure what happened, but when I click on debug and have it perform <code>make</code> it complains about the R file and it seems like it doesn't generate it.</p>
  
  <p>The only way it works is if I click on <code>Build &gt; Rebuild Project</code>...problem is that it takes a long time for that to go through. </p>
  
  <p>Is there anything I am missing? I updated the Android SDK tools, etc. as per some of the other suggestions?</p>