Xcode 6 Memory Leaks Instrument doesn't work
Seems like is a bug on iOS8 and not on Xcode. I have Xcode6.1 and the memory leak profiler seems to work on iOS7.
As a workaround until Apple fix this (already reported the bug and was marked as duplicate) you can profile your memory leaks using a simulator.
This issue seems to occur only on my iOS 8.x devices.
I also submitted a bug report but in the meantime I have it working with the following configuration :
- Xcode 6.1
- iPhone 4 with iOS 6.1.3
This is still a workaround though as you can hardly debug any iOS 8 related feature and analyzing leaks on an old device like that is a real pain.