How to find the cause of an exception - ios

Question

I am trying to debug a crash whenever an iOS document provider extension is started. As it is a extension I am not able to debug it correctly, and this error log is the best i was able to get out of the device. How can i see what is throwing the exception (or what the assertion is) when none of the methods that get called are mine.
Incident Identifier: 0B4EA724-9AFB-4EE3-B752-7E1FDF3B9A75
CrashReporter Key: ac4cdaa3c5ddd65a3bffef5cc28903f683f0309d
Hardware Model: iPad3,1
Process: FileProvider [1100]
Path: /private/var/containers/Bundle/Application/CEDD148D-420D-4BE8-ABF8-8E83F6385ABC/Privat.app/PlugIns/FileProvider.appex/FileProvider
Identifier: com.privat.cloud.FileProvider
Version: 1 (2.5.6)
Code Type: ARM (Native)
Parent Process: launchd [1]
Date/Time: 2017-02-09 15:19:03.03 +0100
Launch Time: 2017-02-09 15:19:02.02 +0100
OS Version: iOS 9.3.5 (13G36)
Report Version: 105
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Triggered by Thread: 0
Filtered syslog:
None found
Last Exception Backtrace:
0 CoreFoundation 0x22673916 __exceptionPreprocess + 122
1 libobjc.A.dylib 0x21e0ee12 objc_exception_throw + 34
2 CoreFoundation 0x226737ec +[NSException raise:format:arguments:] + 100
3 Foundation 0x22e57524 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 88
4 UIKit 0x26fc83e0 -[UIDocumentPickerExtensionViewController _prepareWithExtensionInfo:completionHandler:] + 504
5 CoreFoundation 0x226784c0 __invoking___ + 64
6 CoreFoundation 0x2259e878 -[NSInvocation invoke] + 288
7 CoreFoundation 0x225a22f2 -[NSInvocation invokeWithTarget:] + 46
8 UIKit 0x27489390 -[_UIViewServiceImplicitAnimationDecodingProxy forwardInvocation:] + 252
9 CoreFoundation 0x22676d7e ___forwarding___ + 346
10 CoreFoundation 0x225a2234 _CF_forwarding_prep_0 + 20
11 CoreFoundation 0x226784c0 __invoking___ + 64
12 CoreFoundation 0x2259e878 -[NSInvocation invoke] + 288
13 CoreFoundation 0x225a22f2 -[NSInvocation invokeWithTarget:] + 46
14 UIKit 0x27408b32 -[_UIQueueingProxy forwardInvocation:] + 370
15 CoreFoundation 0x22676d7e ___forwarding___ + 346
16 CoreFoundation 0x225a2234 _CF_forwarding_prep_0 + 20
17 CoreFoundation 0x226784c0 __invoking___ + 64
18 CoreFoundation 0x2259e878 -[NSInvocation invoke] + 288
19 CoreFoundation 0x225a22f2 -[NSInvocation invokeWithTarget:] + 46
20 CoreFoundation 0x22676d7e ___forwarding___ + 346
21 CoreFoundation 0x225a2234 _CF_forwarding_prep_0 + 20
22 CoreFoundation 0x226784c0 __invoking___ + 64
23 CoreFoundation 0x2259e878 -[NSInvocation invoke] + 288
24 CoreFoundation 0x225a22f2 -[NSInvocation invokeWithTarget:] + 46
25 CoreFoundation 0x22676d7e ___forwarding___ + 346
26 CoreFoundation 0x225a2234 _CF_forwarding_prep_0 + 20
27 CoreFoundation 0x226784c0 __invoking___ + 64
28 CoreFoundation 0x2259e878 -[NSInvocation invoke] + 288
29 FrontBoardServices 0x23d16c02 __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 14
30 FrontBoardServices 0x23d16ab4 -[FBSSerialQueue _performNext] + 220
31 FrontBoardServices 0x23d16db4 -[FBSSerialQueue _performNextFromRunLoopSource] + 44
32 CoreFoundation 0x22635dfa __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 10
33 CoreFoundation 0x226359e8 __CFRunLoopDoSources0 + 448
34 CoreFoundation 0x22633d56 __CFRunLoopRun + 790
35 CoreFoundation 0x22583224 CFRunLoopRunSpecific + 516
36 CoreFoundation 0x22583010 CFRunLoopRunInMode + 104
37 GraphicsServices 0x23b73ac4 GSEventRunModal + 156
38 UIKit 0x26c57184 UIApplicationMain + 140
39 libxpc.dylib 0x223cd07c _xpc_objc_main + 700
40 libxpc.dylib 0x223ce730 xpc_main + 164
41 Foundation 0x22f74790 -[NSXPCListener resume] + 160
42 PlugInKit 0x28afe128 -[PKService run] + 504
43 PlugInKit 0x28afddf6 +[PKService main] + 54
44 PlugInKit 0x28afe15c +[PKService _defaultRun:arguments:] + 16
45 libextension.dylib 0x22db37c8 NSExtensionMain + 44
46 libdyld.dylib 0x2222b86e tlv_get_addr + 42
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libsystem_kernel.dylib 0x222fec5c __pthread_kill + 8
1 libsystem_pthread.dylib 0x223a8732 pthread_kill + 62
2 libsystem_c.dylib 0x222930ac abort + 108
3 libc++abi.dylib 0x21deaae4 __cxa_bad_cast + 0
4 libc++abi.dylib 0x21e0369e default_terminate_handler() + 266
5 libobjc.A.dylib 0x21e0f0b0 _objc_terminate() + 192
6 libc++abi.dylib 0x21e00e16 std::__terminate(void (*)()) + 78
7 libc++abi.dylib 0x21e008f8 __cxa_increment_exception_refcount + 0
8 libobjc.A.dylib 0x21e0ef5e objc_exception_rethrow + 42
9 CoreFoundation 0x225832ae CFRunLoopRunSpecific + 654
10 CoreFoundation 0x22583014 CFRunLoopRunInMode + 108
11 GraphicsServices 0x23b73ac8 GSEventRunModal + 160
12 UIKit 0x26c57188 UIApplicationMain + 144
13 libxpc.dylib 0x223cd080 _xpc_objc_main + 704
14 libxpc.dylib 0x223ce734 xpc_main + 168
15 Foundation 0x22f74794 service_connection_handler + 0
16 PlugInKit 0x28afe12c -[PKService run] + 508
17 PlugInKit 0x28afddfa +[PKService main] + 58
18 PlugInKit 0x28afe160 +[PKService _defaultRun:arguments:] + 20
19 libextension.dylib 0x22db37cc NSExtensionMain + 48
20 libdyld.dylib 0x2222b872 start + 2
Thread 1:
0 libsystem_kernel.dylib 0x222ff864 __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x223a5b34 _pthread_wqthread + 1036
2 libsystem_pthread.dylib 0x223a5718 start_wqthread + 8
Thread 2 name: Dispatch queue: com.apple.libdispatch-manager
Thread 2:
0 libsystem_kernel.dylib 0x223002f8 kevent_qos + 24
1 libdispatch.dylib 0x221f5d60 _dispatch_mgr_invoke + 256
2 libdispatch.dylib 0x221f5abe _dispatch_mgr_thread$VARIANT$mp + 38
Thread 3:
0 libsystem_kernel.dylib 0x222ff864 __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x223a5b34 _pthread_wqthread + 1036
2 libsystem_pthread.dylib 0x223a5718 start_wqthread + 8
Thread 4:
0 libsystem_kernel.dylib 0x222ff864 __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x223a5b34 _pthread_wqthread + 1036
2 libsystem_pthread.dylib 0x223a5718 start_wqthread + 8
Thread 5:
0 libsystem_kernel.dylib 0x222ff864 __workq_kernreturn + 8
1 libsystem_pthread.dylib 0x223a5b34 _pthread_wqthread + 1036
2 libsystem_pthread.dylib 0x223a5718 start_wqthread + 8
Thread 6 name: com.apple.coremedia.player.async
Thread 6:
0 libsystem_kernel.dylib 0x222ea920 semaphore_wait_trap + 8
1 libdispatch.dylib 0x221f294a _dispatch_semaphore_wait_slow + 190
2 MediaToolbox 0x279571ec fpa_AsyncMovieControlThread + 1916
3 CoreMedia 0x2462b9b8 figThreadMain + 208
4 libsystem_pthread.dylib 0x223a785a _pthread_body + 138
5 libsystem_pthread.dylib 0x223a77ce _pthread_start + 110
6 libsystem_pthread.dylib 0x223a5724 thread_start + 8
Thread 0 crashed with ARM Thread State (32-bit):
r0: 0x00000000 r1: 0x00000000 r2: 0x00000000 r3: 0x00000000
r4: 0x00000006 r5: 0x395c3000 r6: 0x38803304 r7: 0x0037e378
r8: 0x14582d00 r9: 0x21e048fd r10: 0x3428ff05 r11: 0x14582d24
ip: 0x00000148 sp: 0x0037e36c lr: 0x223a8733 pc: 0x222fec5c
cpsr: 0x00000010
If i setup a global exception breakpoint i get this, and it is not helpful:
libobjc.A.dylib`objc_exception_throw:
-> 0x23c5edf0 <+0>: push {r4, r5, r6, r7, lr}
0x23c5edf2 <+2>: add r7, sp, #0xc
0x23c5edf4 <+4>: .long 0x0d00e92d ; unknown opcode
0x23c5edf8 <+8>: .long 0x6dfaf5ad ; unknown opcode
0x23c5edfc <+12>: mov r5, r0
0x23c5edfe <+14>: movs r0, #0x10
0x23c5ee00 <+16>: bl 0x23c5027c ; __cxa_allocate_exception