title: flutter debug on ios simulator not working
body: <p>crash when build ios,here is logs:</p>
  
  <pre><code>Xcode build done.                                            7.1s
  [VERBOSE-2:shell.cc(178)] Dart Error: Can't load Kernel binary: Invalid kernel binary format version.
  [VERBOSE-2:engine.cc(176)] Could not prepare to run the isolate.
  [VERBOSE-2:engine.cc(123)] Engine not prepare and launch isolate.
  [VERBOSE-2:FlutterEngine.mm(294)] Could not launch engine with configuration.
  Lost connection to device.
  </code></pre>
  
  <p>android is OK, is there configure wrong?</p>