title: xcodebuild can't connect to the Simulator
body: <p>I get errors like this:</p>
  
  <pre><code>2014-10-16 13:14:50.996 xcodebuild[6775:1007] [MT] iPhoneSimulator: Unable to connect to "com.apple.instruments.deviceservice.lockdown" (Error Domain=com.apple.CoreSimulator.SimError Code=146 "Unable to lookup in current state: Shutdown" UserInfo=0x7fabd4043b30 {NSLocalizedDescription=Unable to lookup in current state: Shutdown})
  </code></pre>
  
  <p>I'm using Xcode 6.0.1 and am trying to run my tests via Jenkins. I only have this problem from the command line: running the tests in Xcode is fine.</p>
  
  <p>I've tried deleting the contents of <code>DerivedData</code>, uninstalling and reinstalling Xcode, and rebooting the machine – nothing seems to help.</p>