I just released an OSX app to the App Store, and reports are coming in that it crashes on OSX 10.9.5
Here is the relevant information from a user crash report:
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000050
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 libdispatch.dylib 0x00007fff83955eeb dispatch_async_f + 3
1 de.jakobpenca.sdsdrop 0x00000001048168e0 0x10480e000 + 35040
2 de.jakobpenca.sdsdrop 0x0000000104843c0b 0x10480e000 + 220171
3 libdispatch.dylib 0x00007fff839561bb _dispatch_call_block_and_release + 12
4 libdispatch.dylib 0x00007fff8395328d _dispatch_client_callout + 8
5 libdispatch.dylib 0x00007fff8395aef0 _dispatch_main_queue_callback_4CF + 333
6 com.apple.CoreFoundation 0x00007fff81a164f9 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
7 com.apple.CoreFoundation 0x00007fff819d1714 __CFRunLoopRun + 1636
8 com.apple.CoreFoundation 0x00007fff819d0e75 CFRunLoopRunSpecific + 309
9 com.apple.HIToolbox 0x00007fff87e6aa0d RunCurrentEventLoopInMode + 226
10 com.apple.HIToolbox 0x00007fff87e6a7b7 ReceiveNextEventCommon + 479
11 com.apple.HIToolbox 0x00007fff87e6a5bc _BlockUntilNextEventMatchingListInModeWithFilter + 65
12 com.apple.AppKit 0x00007fff84d1c24e _DPSNextEvent + 1434
13 com.apple.AppKit 0x00007fff84d1b89b -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 122
14 com.apple.AppKit 0x00007fff84d0f99c -[NSApplication run] + 553
15 com.apple.AppKit 0x00007fff84cfa783 NSApplicationMain + 940
16 libdyld.dylib 0x00007fff8ce8b5fd start + 1
Thread 0 crashed with X86 Thread State (64-bit):
rax: 0x00006080002781c0 rbx: 0x000060800024bc40 rcx: 0xffff9f7fffdb4301 rdx: 0x00007fff839561af
rdi: 0x0000000000000000 rsi: 0x00006080002781c0 rbp: 0x00007fff5b3f0420 rsp: 0x00007fff5b3f0398
r8: 0x00000000000000ff r9: 0xffff9f7fffdb43bf r10: 0x00007f8cbb039fa0 r11: 0x00007fff71218628
r12: 0x0000000000000000 r13: 0x00007fff8cf5c0d0 r14: 0x00007fff8cf59080 r15: 0x000060800024bc40
rip: 0x00007fff83955eeb rfl: 0x0000000000010206 cr2: 0x0000000000000050
I don't have access to a Mavericks machine, and trouble extracting meaningful information from that report.
Does this look like unsupported API usage in libdispatch? Or does this just mean the crash happened somewhere inside a dispatched block?
I do use dispatch_async() around the time of crash.
The app was built on OSX 10.11.3 with Xcode 7.2, latest SDK, 10.9 as deployment target. Can I scan my code for unsupported API usage?
I don't have access to a Mavericks machine
and
[The app was released with] 10.9 as deployment target
You don't need a physical machine (or boot drive) for every version of OS X you wish to support.
Get a copy of VMWare/Parallels/Virtual Box now; build two VMs, one Mavericks and one Yosemite; and test your app on both.