understand iOS crash log

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.

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.