iOS app crash only when not debugging - objective-c

Question

I am using testflight to test my app, and I have a crash that only occurs when the app is built for ad-hoc and distributed through test flight. The relevant crash report details are:
Date/Time: 2012-06-11 09:00:34.638 +0800
OS Version: iPhone OS 5.1.1 (9B206)
Report Version: 104
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x00000009
Crashed Thread: 0
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libobjc.A.dylib 0x34e74f78 objc_msgSend + 16
1 appName 0x0002963e __24-[XYPieChart reloadData]_block_invoke_0168 (XYPieChart.m:321)
2 libdispatch.dylib 0x30295c52 _dispatch_call_block_and_release + 6
3 libdispatch.dylib 0x302a0e8a _dispatch_main_queue_callback_4CF$VARIANT$up + 190
4 CoreFoundation 0x371482a6 __CFRunLoopRun + 1262
5 CoreFoundation 0x370cb49e CFRunLoopRunSpecific + 294
6 CoreFoundation 0x370cb366 CFRunLoopRunInMode + 98
7 GraphicsServices 0x3388a432 GSEventRunModal + 130
8 UIKit 0x30e77cce UIApplicationMain + 1074
9 appName 0x00003b20 main (main.m:14)
10 appName 0x00003ad8 0x1000 + 10968
and the code that is referenced - (XYPieChart.m:321)
[CATransaction begin];
[CATransaction setAnimationDuration:_animationSpeed];
[_pieView setUserInteractionEnabled:NO];
__block NSMutableArray *layersToRemove = nil;
[CATransaction setCompletionBlock:^{
if (layersToRemove) {
[layersToRemove enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
if (obj)
[obj removeFromSuperlayer];
}];
[layersToRemove removeAllObjects];
}
for(SliceLayer *layer in _pieView.layer.sublayers)
{
[layer setZPosition:kDefaultSliceZOrder];
}
[_pieView setUserInteractionEnabled:YES];
}];
BOOL isOnStart = ([slicelayers count] == 0 && sliceCount);
NSInteger diff = sliceCount - [slicelayers count];
layersToRemove = [NSMutableArray arrayWithArray:slicelayers];
BOOL isOnEnd = ([slicelayers count] && (sliceCount == 0 || sum <= 0));
if(isOnEnd)
{
for(SliceLayer *layer in _pieView.layer.sublayers){
[self updateLabelForLayer:layer value:0];
[layer createArcAnimationForKey:#"startAngle"
fromValue:[NSNumber numberWithDouble:_startPieAngle]
toValue:[NSNumber numberWithDouble:_startPieAngle]
Delegate:self];
[layer createArcAnimationForKey:#"endAngle"
fromValue:[NSNumber numberWithDouble:_startPieAngle]
toValue:[NSNumber numberWithDouble:_startPieAngle]
Delegate:self];
}
[CATransaction commit];
return;
}
I would be able to track down the problem if I could reproduce it when debugging but it only seems to occur when built for ad-hoc. Thanks!
Edit:
Using the simulator, I have tracked down the problem to a EXC_BAD_ACCESS at this line
[layersToRemove enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

Answer 1

I had a similar problem and tried changing the project build settings, but it didn't work for me. Eventually solved my problem by changing the compiler optimization level setting for the release:
In Build Settings, go to the LLVM compiler 4.2 - Code Generation section, look for the Optimization Level option and change the Release setting from Fastest, Smallest [-Os] to None [-O0].
Hope this helps!

Answer 2

Change your Xcode Scheme so that you can Test and Debug a Release build, which uses the same compiler optimizations as your Ad Hoc build. Debugging a Debug build does not.

Answer 3

I ended up working out the problem. In my compiler settings, somehow, ARC wasn't enabled for Ad-Hoc builds resulting in weird behaviour. Before I worked this out, allocating the __block variable worked because in non-ARC environments, __block variables are not retained automatically.
Changed compiler settings so that all builds use ARC and everything was fixed.

Answer 4

In my case it was the "Enable Zombie Objects" setting that prevented the crash in debug mode. Debuggin without this setting made the app also crash in the debugger making it easy to find the culprit.
So I would advice to disable all settings in the "diagnostics" menu and set the optimizations to -Os and make a final test before releasing. Or as hotpaw2 pointed out, build in release mode. But this did not work for me due to issues with the certificate settings.