Xamarin iOS iPad App is crashing, unexplained

Question

we are creating a large iOS App with Xamarin. Since a few days, we have the problem that the app is crashing in absolutely unexpected ways. We don't get a log from the Xamarin debugger, it is completly empty. Only the stop button switches to play ;) The only thing we have is the attached XCode Console Log. But for me it is not possible to find out what has happened.

The problem is not reproduceable and it happens in different places of the app. Did somebody saw a similiar problem and found out a solution for this?

Mar 21 15:01:15  Ios[312] <Error>: Stacktrace:
Mar 21 15:01:15  Ios[312] <Error>:   at <unknown> <0xffffffff>
Mar 21 15:01:15  Ios[312] <Error>:   at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication.UIApplicationMain (int,string[],intptr,intptr) <0xffffffff>
Mar 21 15:01:15  Ios[312] <Error>:   at MonoTouch.UIKit.UIApplication.Main (string[],string,string) [0x0004c] in /Developer/MonoTouch/Source/monotouch/src/UIKit/.pmcs-compat.UIApplication.cs:38
Mar 21 15:01:15  Ios[312] <Error>:   at Ios.Application.Main (string[]) [0x00008] in /Users/admin/Projects/XXX/Source/Ios/Main.cs:15
Mar 21 15:01:15  Ios[312] <Error>:   at (wrapper runtime-invoke) object.runtime_invoke_dynamic (intptr,intptr,intptr,intptr) <0xffffffff>
Mar 21 15:01:15  Ios[312] <Error>: 
    Native stacktrace:
Mar 21 15:01:15  Ios[312] <Error>:  0   Ios                                 0x00cfdb69 mono_handle_native_sigsegv + 260
Mar 21 15:01:15  Ios[312] <Error>:  1   Ios                                 0x00d06d09 mono_sigsegv_signal_handler + 176
Mar 21 15:01:15  Ios[312] <Error>:  2   libsystem_platform.dylib            0x38b18063 _sigtramp + 42
Mar 21 15:01:15  Ios[312] <Error>:  3   UIKit                               0x307b8cf5 <redacted> + 76
Mar 21 15:01:15  Ios[312] <Error>:  4   CoreFoundation                      0x2de27504 <redacted> + 68
Mar 21 15:01:15  Ios[312] <Error>:  5   CoreFoundation                      0x2dd71dfb <redacted> + 282
Mar 21 15:01:15  Ios[312] <Error>:  6   CoreFoundation                      0x2dd75593 <redacted> + 50
Mar 21 15:01:15  Ios[312] <Error>:  7   WebKit                              0x368b2ee7 <redacted> + 222
Mar 21 15:01:15  Ios[312] <Error>:  8   CoreFoundation                      0x2de26069 <redacted> + 352
Mar 21 15:01:15  Ios[312] <Error>:  9   CoreFoundation                      0x2dd754d8 _CF_forwarding_prep_0 + 24
Mar 21 15:01:15  Ios[312] <Error>:  10  CoreFoundation                      0x2de27504 <redacted> + 68
Mar 21 15:01:15  Ios[312] <Error>:  11  CoreFoundation                      0x2dd71dfb <redacted> + 282
Mar 21 15:01:15  Ios[312] <Error>:  12  WebCore                             0x35f101bd <redacted> + 100
Mar 21 15:01:15  Ios[312] <Error>:  13  CoreFoundation                      0x2ddef183 <redacted> + 14
Mar 21 15:01:15  Ios[312] <Error>:  14  CoreFoundation                      0x2ddee653 <redacted> + 206
Mar 21 15:01:15  Ios[312] <Error>:  15  CoreFoundation                      0x2ddece47 <redacted> + 622
Mar 21 15:01:15  Ios[312] <Error>:  16  CoreFoundation                      0x2dd57c27 CFRunLoopRunSpecific + 522
Mar 21 15:01:15  Ios[312] <Error>:  17  CoreFoundation                      0x2dd57a0b CFRunLoopRunInMode + 106
Mar 21 15:01:15  Ios[312] <Error>:  18  GraphicsServices                    0x32a2b283 GSEventRunModal + 138
Mar 21 15:01:15  Ios[312] <Error>:  19  UIKit                               0x305fb049 UIApplicationMain + 1136
Mar 21 15:01:15  Ios[312] <Error>:  20  Ios                                 0x004ac450 wrapper_managed_to_native_MonoTouch_UIKit_UIApplication_UIApplicationMain_int_string___intptr_intptr + 272
Mar 21 15:01:15  Ios[312] <Error>:  21  Ios                                 0x0046335c MonoTouch_UIKit_UIApplication_Main_string___string_string + 300
Mar 21 15:01:15  Ios[312] <Error>:  22  Ios                                 0x0000bcc8 Ios_Application_Main_string__ + 172
Mar 21 15:01:15  Ios[312] <Error>:  23  Ios                                 0x0064c558 wrapper_runtime_invoke_object_runtime_invoke_dynamic_intptr_intptr_intptr_intptr + 200
Mar 21 15:01:15  Ios[312] <Error>:  24  Ios                                 0x00d08e25 mono_jit_runtime_invoke + 1196
Mar 21 15:01:15  Ios[312] <Error>:  25  Ios                                 0x00d46e8d mono_runtime_invoke + 88
Mar 21 15:01:15  Ios[312] <Error>:  26  Ios                                 0x00d4aa67 mono_runtime_exec_main + 282
Mar 21 15:01:15  Ios[312] <Error>:  27  Ios                                 0x00d4a8a7 mono_runtime_run_main + 474
Mar 21 15:01:15  Ios[312] <Error>:  28  Ios                                 0x00cf710d mono_jit_exec + 48
Mar 21 15:01:15  Ios[312] <Error>:  29  Ios                                 0x00d97fe8 main + 2464
Mar 21 15:01:15  Ios[312] <Error>:  30  Ios                                 0x0000b028 start + 40
Mar 21 15:01:15  Ios[312] <Error>: 
    =================================================================
    Got a SIGSEGV while executing native code. This usually indicates
    a fatal error in the mono runtime or one of the native libraries 
    used by your application.
    =================================================================

Here is how I've fixed parts before: http://stackoverflow.com/a/12854350/183422 — Rolf Bjarne Kvinge, Mar 24 '14 at 18:30
Sounds like you need to roll back your code to a few days ago and incrementally re-introduce your changes. — NovaJoe, Mar 26 '14 at 16:11

score 0 · Answer 1 · answered Apr 11 '14 at 21:56

It seems that you introduce some code that will parse before the compiler time. It's possible in Android (JIT just-in compiler time) but not with iOS (AOT ahead of time). Read what Xamarin wrote in his page http://docs.xamarin.com/guides/ios/advanced_topics/limitations/

Since the iPhone's kernel prevents an application from generating code dynamically Mono on the iPhone does not support any form of dynamic code generation.

Hope I help!

Xamarin iOS iPad App is crashing, unexplained

1 Answers1