title: XCode alert says UPDATING_LOCKED_* on launch
body: <p>This is on OS X Yosemite. It appears when I try launching Xcode.</p>
  
  <p><img src="https://i.stack.imgur.com/H8zHF.png" alt="Screenshot of dialog: UPDATING_LOCKED_TITLE UPDATING_LOCKED_MESSAGE UPDATING_LOCKED_DEFAULT_BUTTON"></p>
  
  <p>There are no updates shown in the App Store and there are no active downloading updates shown, either. Not exactly the pinnacle of Apple's great user experiences.</p>
  
  <p>I hope I don't have to do a clean install…</p>