Sometimes it takes several seconds to load the scope chain sections if many call frames are navigated or the system is under load. We could put the spinner in there that's used in the main content browser area. Repro steps (on a fast machine): 1. Go to Wikipedia with Inspector ope 2. Turn on "pause on all exceptions" 3. Navigate around until you get a call stack >20 frames 4. Start at the top call frame, and quickly key down through all the call frames. It will take several seconds for the backend to catch up. In the meantime, it just looks like there is nothing in the scope chain sidebar.
<rdar://problem/19817197>