Profiling my iOS 8 app in Xcode 6 Instruments will run the app for about 5 seconds and then freeze. The profiler will still run after that point but the app is frozen and unusable. Happens on device and simulator and regardless of which profiler I'm using (timer, leaks, etc.)
Running the app from the debugger or an ad hoc build works fine. Profiling with iOS 7 works fine as well.
Any idea why this may be happening? Is Instruments broken?
Same issue here:
Application hangs when profiling with instrument in XCode 6.0.1
Looks like if you remove all the NSLog statements it will fix it. For me this is happening only on iOS 8, i have no problems on iOS 7.