title: XCode LLDB command po can't output info
body: <p>I set a breakpoint to see the value of <code>string</code> in console .But the <code>po</code>command doesn't work. A little earlier it was fine, but now left is OK and right is going wrong – why and how? Here is the pic:</p>
  
  <p><a href="https://i.stack.imgur.com/Bqgvi.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Bqgvi.jpg" alt="enter image description here"></a></p>