title: Core Data migration failing on Release builds only
body: <p>I added an attribute to a Core Data model (iOS).  I was on version 2, so I added a new model and saved the new attribute under version 3.</p>
  
  <p>My loading code is standard (initializing a MOM using <code>initWithContentsOfURL:</code> pointing at my <code>.momd</code> directory inside my bundle), then passing that MOM to a <code>NSPersistentStoreCoordinator</code>.</p>
  
  <p>Then, I download my app from the App Store, run it, and then try to test the migration.  Lightweight migration is working fine on my Simulator and my phone <em>in Debug</em> (tethered to Xcode 4).  </p>
  
  <p>However, when I sync a Release build (using the "Archive" feature on Xcode) using iTunes, my app's data store fails to migrate with this error:</p>
  
  <pre><code>Error Domain=NSCocoaErrorDomain Code=134130 "The operation couldn’t be completed.
  (Cocoa error 134130.)", reason=Can't find model for source store}
  </code></pre>
  
  <p>Worse yet, the store gets lost in some voodoo state where it cannot escape - if I re-tether the device and install a Debug build from Xcode again, I can't "recover" the migration.</p>
  
  <p>The error message above omits the details about my entities.  I can provide that if helpful, but any ideas on what might be wrong here?  I've read just about every question on SO about this error code and so far all of them have failed to produce a result.</p>
  
  <p>I tried a manual migration, but it also yielded an error.  However, since I only added 1 attribute to 1 entity, it doesn't make sense that lightweight migration isn't working.</p>