understand iOS crash log - ios

Question

Could someone please help me understand this crash report. I can't make head or tail of it.
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Triggered by Thread: 8
Last Exception Backtrace:
0 CoreFoundation 0x2ec73fce __exceptionPreprocess + 126
1 libobjc.A.dylib 0x3983dcca objc_exception_throw + 34
2 CoreFoundation 0x2ec73ea8 +[NSException raise:format:arguments:] + 96
3 Foundation 0x2f620d56 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 86
4 UIKit 0x314bce9a -[UIKeyboardTaskQueue waitUntilAllTasksAreFinished] + 166
5 UIKit 0x314cdaf4 -[UIKeyboardImpl prepareForSelectionChange] + 88
6 UIKit 0x314afe10 -[UIFieldEditor setAttributedText:andSetCaretSelectionAfterText:] + 52
7 UIKit 0x314cd77a -[UIFieldEditor setText:andSetCaretSelectionAfterText:] + 130
8 UIKit 0x314cd508 -[UITextField setText:] + 220
9 UIKit 0x316852c8 -[UISearchBar setText:] + 40
10 Farm Hand 0x0009b906 0x7000 + 608518
11 Foundation 0x2f65ca5a __NSThread__main__ + 1058
12 libsystem_pthread.dylib 0x39e69914 _pthread_body + 136
13 libsystem_pthread.dylib 0x39e69886 _pthread_start + 98
14 libsystem_pthread.dylib 0x39e67aa0 thread_start + 4
Thread 0:
0 libsystem_kernel.dylib 0x39deda58 mach_msg_trap + 20
1 libsystem_kernel.dylib 0x39ded854 mach_msg + 44
2 CoreFoundation 0x2ec3e896 __CFRunLoopServiceMachPort + 150
3 CoreFoundation 0x2ec3d002 __CFRunLoopRun + 850
4 CoreFoundation 0x2eba7f0a CFRunLoopRunSpecific + 518
5 CoreFoundation 0x2eba7cee CFRunLoopRunInMode + 102
6 GraphicsServices 0x33acd65e GSEventRunModal + 134
7 UIKit 0x314f3168 UIApplicationMain + 1132
8 Farm Hand 0x0009de44 0x7000 + 618052
9 libdyld.dylib 0x39d4aab4 start + 0
Thread 1:
0 libsystem_kernel.dylib 0x39ded808 kevent64 + 24
1 libdispatch.dylib 0x39d2f078 _dispatch_mgr_invoke + 228
2 libdispatch.dylib 0x39d2edfe _dispatch_mgr_thread$VARIANT$mp + 34
Thread 2:
0 libsystem_kernel.dylib 0x39deda58 mach_msg_trap + 20
1 libsystem_kernel.dylib 0x39ded854 mach_msg + 44
2 CoreFoundation 0x2ec3e896 __CFRunLoopServiceMachPort + 150
3 CoreFoundation 0x2ec3cfbc __CFRunLoopRun + 780
4 CoreFoundation 0x2eba7f0a CFRunLoopRunSpecific + 518
5 CoreFoundation 0x2ebeb9fe CFRunLoopRun + 94
6 CoreMotion 0x2f2653a8 ___lldb_unnamed_function1423$$CoreMotion + 724
7 libsystem_pthread.dylib 0x39e69916 _pthread_body + 138
8 libsystem_pthread.dylib 0x39e69886 _pthread_start + 98
9 libsystem_pthread.dylib 0x39e67aa0 thread_start + 4
Thread 3 name: com.apple.CFSocket.private
Thread 3:
0 libsystem_kernel.dylib 0x39e00434 __select + 20
1 CoreFoundation 0x2ec42758 __CFSocketManager + 480
2 libsystem_pthread.dylib 0x39e69916 _pthread_body + 138
3 libsystem_pthread.dylib 0x39e69886 _pthread_start + 98
4 libsystem_pthread.dylib 0x39e67aa0 thread_start + 4
Thread 4:
0 libsystem_kernel.dylib 0x39df11a8 kevent + 24
1 ExternalAccessory 0x2f58567a -[EAInputStream _readInputFromAccThread] + 382
2 Foundation 0x2f65ca5a __NSThread__main__ + 1058
3 libsystem_pthread.dylib 0x39e69916 _pthread_body + 138
4 libsystem_pthread.dylib 0x39e69886 _pthread_start + 98
5 libsystem_pthread.dylib 0x39e67aa0 thread_start + 4
Thread 5:
0 libsystem_kernel.dylib 0x39e00c70 __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x39e67bda _pthread_wqthread + 306
2 libsystem_pthread.dylib 0x39e67a94 start_wqthread + 4
Thread 6:
0 libsystem_kernel.dylib 0x39e00c70 __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x39e67bda _pthread_wqthread + 306
2 libsystem_pthread.dylib 0x39e67a94 start_wqthread + 4
Thread 7:
0 libsystem_kernel.dylib 0x39e00c70 __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x39e67bda _pthread_wqthread + 306
2 libsystem_pthread.dylib 0x39e67a94 start_wqthread + 4
Thread 8 Crashed:
0 libsystem_kernel.dylib 0x39e001f0 __pthread_kill + 8
1 libsystem_pthread.dylib 0x39e6a792 pthread_kill + 54
2 libsystem_c.dylib 0x39db0fd8 abort + 72
3 libc++abi.dylib 0x390dfcd2 abort_message + 70
4 libc++abi.dylib 0x390f86e0 default_terminate_handler() + 248
5 libobjc.A.dylib 0x3983df62 _objc_terminate() + 190
6 libc++abi.dylib 0x390f61c4 std::__terminate(void (*)()) + 76
7 libc++abi.dylib 0x390f5a18 __cxa_throw + 112
8 libobjc.A.dylib 0x3983dd9e objc_exception_throw + 246
9 CoreFoundation 0x2ec73ea8 +[NSException raise:format:arguments:] + 96
10 Foundation 0x2f620d56 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 86
11 UIKit 0x314bce9a -[UIKeyboardTaskQueue waitUntilAllTasksAreFinished] + 166
12 UIKit 0x314cdaf4 -[UIKeyboardImpl prepareForSelectionChange] + 88
13 UIKit 0x314afe10 -[UIFieldEditor setAttributedText:andSetCaretSelectionAfterText:] + 52
14 UIKit 0x314cd77a -[UIFieldEditor setText:andSetCaretSelectionAfterText:] + 130
15 UIKit 0x314cd508 -[UITextField setText:] + 220
16 UIKit 0x316852c8 -[UISearchBar setText:] + 40
17 Farm Hand 0x0009b908 0x7000 + 608520
18 Foundation 0x2f65ca5a __NSThread__main__ + 1058
19 libsystem_pthread.dylib 0x39e69916 _pthread_body + 138
20 libsystem_pthread.dylib 0x39e69886 _pthread_start + 98
21 libsystem_pthread.dylib 0x39e67aa0 thread_start + 4
Thread 8 crashed with ARM Thread State (32-bit):
r0: 0x00000000 r1: 0x00000000 r2: 0x00000000 r3: 0x00002060
r4: 0x00000006 r5: 0x04d2f000 r6: 0x00000000 r7: 0x04d2dd14
r8: 0x1804a3c0 r9: 0x00000001 r10: 0x31ae10c8 r11: 0x00000000
ip: 0x00000148 sp: 0x04d2dd08 lr: 0x39e6a797 pc: 0x39e001f0
cpsr: 0x00000010
I'm using the ExternalAccessory framework which I've had problems with in the past and the App crashed whilst receiving data from a bluetooth connected external device. However, I can't tell if that was what caused the crash.
Thanks in advance.

Answer 1

The crash was caused by something that went wrong inside of:
[UIKeyboardTaskQueue waitUntilAllTasksAreFinished]
which was called in the process of executing:
[UISearchBar setText:]
So, it seems, you typed something in a search bar, and the app crashed.