We've been getting these errors randomly in our application over the past several months and they show up in Bugsnag. They definitely cause crashes as we've had internal members of our team report the crash but are then unable to reproduce them. Here's a full trace:
EXC_BAD_ACCESS Attempted to dereference garbage pointer 0x167f4beb8.
/usr/lib/libobjc.A.dylib objc_msgSend
Frameworks/Foundation.framework/Foundation -[NSObject(NSKeyValueObservingPrivate) _changeValueForKeys:count:maybeOldValuesDict:usingBlock:]
Frameworks/Foundation.framework/Foundation -[NSObject(NSKeyValueObservingPrivate) _changeValueForKey:key:key:usingBlock:]
Frameworks/Foundation.framework/Foundation -[NSOperationQueue setMaxConcurrentOperationCount:]
GreatJonesStreet-Prod mh_execute_header
GreatJonesStreet-Prod mh_execute_header
GreatJonesStreet-Prod mh_execute_header
/usr/lib/system/libdispatch.dylib __dispatch_call_block_and_release
/usr/lib/system/libdispatch.dylib __dispatch_client_callout
/usr/lib/system/libdispatch.dylib __dispatch_queue_override_invoke
/usr/lib/system/libdispatch.dylib __dispatch_root_queue_drain
/usr/lib/system/libdispatch.dylib __dispatch_worker_thread3
/usr/lib/system/libsystem_pthread.dylib __pthread_wqthread
I've read in multiple places that other people are having this issue and Bugsnag (which is so ironic) seems to be the common thing mentioned where it's found. I'm not saying Bugsnag is causing the issue but people keep reporting that they are seeing the crash log in their Bugsnag reports. Just seems oddly coincidental.
Here's another:
EXC_BAD_ACCESS Attempted to dereference garbage pointer 0xa8a94beb8.
/usr/lib/libobjc.A.dylib objc_msgSend
Frameworks/Foundation.framework/Foundation -[NSObject(NSKeyValueObservingPrivate) _changeValueForKeys:count:maybeOldValuesDict:usingBlock:]
Frameworks/Foundation.framework/Foundation -[NSObject(NSKeyValueObservingPrivate) _changeValueForKey:key:key:usingBlock:]
Frameworks/Foundation.framework/Foundation -[NSOperationQueue setMaxConcurrentOperationCount:]
GreatJonesStreet mh_execute_header
GreatJonesStreet mh_execute_header
GreatJonesStreet mh_execute_header
/usr/lib/system/libdispatch.dylib __dispatch_call_block_and_release
/usr/lib/system/libdispatch.dylib __dispatch_client_callout
/usr/lib/system/libdispatch.dylib __dispatch_queue_override_invoke
/usr/lib/system/libdispatch.dylib __dispatch_root_queue_drain
/usr/lib/system/libdispatch.dylib __dispatch_worker_thread3
/usr/lib/system/libsystem_pthread.dylib __pthread_wqthread
At the time of posting this question, 75 of these errors above have occurred to 56 of our users.
Anyone have any ideas???
