App Crash on UIButtonLabel defaultAttributes

Question

We have an app crash we are trying to resolve, but I am not sure where to start. The issue appears to be with a call to the defaultAttributes of a UIButtonLabel.

It looks like it is a core call to UIKit rather than coming directly from app code. Any advice on what can be checked here to determine the issue or get closer?

Thread : Crashed: com.apple.main-thread
0 libobjc.A.dylib 0x33ab0f66 objc_msgSend + 5
1 UIKit 0x29874a4b -[UIButtonLabel _defaultAttributes] + 154
2 UIKit 0x297d7a81 -[UILabel font] + 120
3 UIKit 0x29aed4d3 -[UILabel _contentInsetsFromFonts] + 250
4 UIKit 0x29c410e3 -[_UILabelLayer updateContentInsets] + 94
5 UIKit 0x29c411b7 -[_UILabelLayer updateContentLayerSize] + 42
6 QuartzCore 0x291e7bd1 CA::Layer::layout_if_needed(CA::Transaction*) + 360
7 QuartzCore 0x291e7a59 CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 16 8 QuartzCore 0x291e7447 CA::Context::commit_transaction(CA::Transaction*) + 222
9 QuartzCore 0x291e7251 CA::Transaction::commit() + 324
10 UIKit 0x297b9699 _afterCACommitHandler + 132
11 CoreFoundation 0x2630c845 CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION + 20
12 CoreFoundation 0x26309f29 __CFRunLoopDoObservers + 276
13 CoreFoundation 0x2630a32b __CFRunLoopRun + 914
14 CoreFoundation 0x26257db1 CFRunLoopRunSpecific + 476
15 CoreFoundation 0x26257bc3 CFRunLoopRunInMode + 106
16 GraphicsServices 0x2d5e2051 GSEventRunModal + 136
17 UIKit 0x29822f01 UIApplicationMain + 1440
18 APPNAME 0x0005120f main (main.m:16)

Answer 1

I had a very similar crash, which was due to a message sent to a deallocated instance. I found that out by enabling zombies.