title: Why is 'Simulate Background Fetch' leading to crash (libsystem_kernel.dylib`mach_msg_trap) since Xcode 8?
body: <p>I'm on macOS Sierra, Xcode 8, and get crashes whenever I try to Simulate Background Fetch on an actual iOS 10 device.  This does NOT occur when using the simulator.  This occurs in all projects, including those freshly created.</p>
  
  <pre><code>    libsystem_kernel.dylib`mach_msg_trap:
      0x18cfec164 &lt;+0&gt;: movn   x16, #0x1e
      0x18cfec168 &lt;+4&gt;: svc    #0x80
  -&gt;  0x18cfec16c &lt;+8&gt;: ret   (Thread 1: signal SIGSTOP)
  </code></pre>
  
  <p>I don't have any other iOS devices to test with; is anyone else experiencing this?</p>