c# ios iphone testflight xamarin.ios

Better MonoTouch crashes with TestFlight

We’ve hooked up TestFlight and the TestFlight SDK with MonoTouch and so far it’s working great.

One thing we’ve noticed is that the crash reports are more geared towards Obj-C apps.

They look like this after you upload a zipped dSYM file:

0 OurApp 0x007a7116 testflight_backtrace + 170
1 OurApp0x007a7c3c TFSignalHandler + 208
2 libsystem_c.dylib 0x34f68538 _sigtramp + 48
3 libsystem_c.dylib 0x34f5df5a pthread_kill + 54
4 libsystem_c.dylib 0x34f56fea abort + 94
5 OurApp 0x007793b3 monoeg_g_logv (goutput.c:137)
6 OurApp 0x0077941f monoeg_g_log (goutput.c:147)
7 OurApp 0x005f1393 get_numerous_trampoline (aot-runtime.c:3447)
8 OurApp 0x005f1b2f mono_aot_get_imt_thunk (aot-runtime.c:3576)
9 OurApp 0x006e2c83 initialize_imt_slot (object.c:1247)
10 OurApp 0x006e321f build_imt_slots (object.c:1371)
11 OurApp 0x006e356f mono_vtable_build_imt_slot (object.c:1439)
12 OurApp 0x005fcf83 mono_convert_imt_slot_to_vtable_slot (mini-trampolines.c:198)
13 OurApp 0x005fd50f common_call_trampoline (mini-trampolines.c:333)
14 OurApp 0x005fe573 mono_vcall_trampoline (mini-trampolines.c:644)
15 OurApp 0x0056a68f generic_trampoline_vcall (mscorlib.dll.6.s:194345)
16 OurApp 0x00416b4f System_Collections_Generic_List_1__ctor_System_Collections_Generic_IEnumerable_1_T (mscorlib.dll.6.s:32014)
17 OurApp 0x0026955b System_Linq_Enumerable_ToList_TSource_System_Collections_Generic_IEnumerable_1_TSource (System.Core.dll.6.s:1917)

So you can tell the general C# function where the crash occurred. (Note: this crash was a bug in MonoTouch 5.0.1 where Linq generics were messed up, seems to be fixed in 5.0.2)

It would be nice to get the full C# stack trace in here, any thoughts on how to do that? I could hook into AppDomain.UnhandledException and put a try-catch around my static void Main method, but wondered if there is a way to report the stack trace out to TestFlight.

I’m not familiar with MonoTouch, but what about using the Remote Logging features of the TestFlight SDK?