title: Under what conditions does Metal shader code "crash?"
body: <p>I'm developing a Metal-based app, and in some cases properly compiled and linked shader code will cause the application to simply crash without throwing any errors.</p>
  
  <p>A "crash" consists of a halt in visual output (in some cases preceded by a short stutter of a couple alternating frames), but otherwise normal procession of the rest of the application. The Xcode performance monitoring utilities report 60fps but 0ms GPU latency, and CPU-side execution continues, with calls to the Metal API still completing successfully.</p>
  
  <p>No errors are reported to the console.</p>
  
  <p>This is extremely difficult to debug, as I have no indication of where in shader code the error is coming from. It would help if I knew under what conditions this is actually supposed to happen, so that I can have a good list of things to check. Otherwise I'm just shooting in the dark whenever this comes up.</p>