title: INSTALL_FAILED_UPDATE_INCOMPATIBLE when using same debug keystore as before
body: <p>We are finally migrating from Eclipse ADT to Android Studio 2.3.2 (yes, I know). </p>
  
  <p>We used a custom debug keystore in Eclipse 
  <a href="https://i.stack.imgur.com/sAPRf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/sAPRf.png" alt="Image of the custom debug keystore settings in Eclipse"></a></p>
  
  <p>I am attempting to use a debug keystore in Android Studio / gradle.</p>
  
  <p>I followed the straightforward directions here: <a href="https://developer.android.com/studio/publish/app-signing.html" rel="nofollow noreferrer" title="Android Developer: App Signing">Android Developer: App Signing</a>
  <a href="https://i.stack.imgur.com/49W2n.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/49W2n.png" alt="Image of app Signing properties in Android Studio"></a>
  <a href="https://i.stack.imgur.com/gYrrq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gYrrq.png" alt="Image of Build Type properties in Android Studio"></a></p>
  
  <p>All the Run configuration settings are defaults. </p>
  
  <p>But when I try to run, I get the following failure: </p>
  
  <pre><code>Failed to finalize session : INSTALL_FAILED_UPDATE_INCOMPATIBLE: Package --redacted-- signatures do not match the previously installed version; ignoring!
  </code></pre>
  
  <p>Yes, I <em>could</em> uninstall the app from my device and reinstall to get it working. <strong>But I don't want to.</strong> I thought the point of having and using a keystore is that you don't have to do that? </p>
  
  <p>Why am I getting INSTALL_FAILED_UPDATE_INCOMPATIBLE even though I'm using the same debug keystore? </p>