ios exception analyse NSInternalInconsistencyException - ios

Question

My app crash with a NSInternalInconsistencyException like this
Exception reason：NSInternalInconsistencyException
Exception name：Can't cancel on a touch that isn't already active!
Exception stack：(
0 CoreFoundation 0x0000000191a4d1d0 <redacted> + 148
1 libobjc.A.dylib 0x000000019048455c objc_exception_throw + 56
2 CoreFoundation 0x0000000191a4d08c <redacted> + 0
3 Foundation 0x000000019250502c <redacted> + 112
4 UIKit 0x0000000197fd1960 <redacted> + 404
5 UIKit 0x0000000197fcf970 <redacted> + 1648
6 libdispatch.dylib 0x00000001908d61fc <redacted> + 24
7 libdispatch.dylib 0x00000001908d61bc <redacted> + 16
8 libdispatch.dylib 0x00000001908e43dc <redacted> + 928
9 libdispatch.dylib 0x00000001908d99a4 <redacted> + 652
10 libdispatch.dylib 0x00000001908e634c <redacted> + 572
11 libdispatch.dylib 0x00000001908e60ac <redacted> + 124
12 libsystem_pthread.dylib 0x0000000190adf2a0 _pthread_wqthread + 1288
13 libsystem_pthread.dylib 0x0000000190aded8c start_wqthread + 4
)
How do i analyse the log? Like What do those number tags mean,"+ 148" "+ 56"...? How to detect the code that have invoked this exception.

Answer 1

Is this a crash from a release build of the app, or do you have it in Xcode? If in Xcode please provide the code causing the crash?
Looking at your report, the line
Can't cancel on a touch that isn't already active!
seems very telling. I would look through your code for anywhere you are interacting with a UITouch object, or perhaps a UIGestureRecognizer. My guess would be that somewhere you are manually calling to cancel an interaction that you should not be, and there is a race condition where that can sometimes happen after the system has already cancelled the touch (or vice versa, I guess).