Several end user crashes reported on Unity Cloud Diagnostics

Unity Cloud Diagnostics is reporting a significant number of Native Crash - __pthread_kill end-user crashes on iOS, and we don’t have much in the way of leads as far as what the reproduction steps are, or what we can even investigate.

Info on this particular instance of the crash:
Editor Version: 2018.4.6f1
OS: iOS 13.1.3
Device: iPhone9,3

And here is the stack trace that we are given, and on which hopefully someone can shed some light.

Native StackTrace:

Thread 0 (crashed)
0   libsystem_kernel.dylib             0x0000000199290ebc __pthread_kill
1   libsystem_c.dylib                  0x0000000199100824 abort
2   bundleidentifier                   0x0000000103bd67f8 -[BITPLCrashReporter generateLiveReportWithThread:]
3   CoreFoundation                     0x0000000199498c94 __handleUncaughtException
4   libobjc.A.dylib                    0x00000001991c134c _objc_terminate()
5   bundleidentifier                   0x0000000103bbe99c BITCrashUncaughtCXXTerminateHandler()
6   libc++abi.dylib                    0x0000000199266304 std::__terminate(void (*)())
7   libc++abi.dylib                    0x0000000199265ed8 __cxa_rethrow
8   libobjc.A.dylib                    0x00000001991c1258 objc_exception_rethrow
9   CoreFoundation                     0x000000019941092c CFRunLoopRunSpecific
10  GraphicsServices                   0x00000001a327c328 GSEventRunModal
11  UIKitCore                          0x000000019d4a66d4 UIApplicationMain
12  bundleidentifier                   0x0000000102c1b3c0 main
13  libdyld.dylib                      0x000000019929b460 start

Thread 1
0   libsystem_kernel.dylib             0x0000000199291a74 __workq_kernreturn
1   libsystem_pthread.dylib            0x00000001991b8ae0 start_wqthread

Thread 2
0   libsystem_kernel.dylib             0x0000000199291a74 __workq_kernreturn
1   libsystem_pthread.dylib            0x00000001991b8ae0 start_wqthread

Thread 3
0   libsystem_pthread.dylib            0x00000001991b8ad8 start_wqthread

Thread 4
0   libsystem_kernel.dylib             0x000000019926f5f4 mach_msg_trap
1   CoreFoundation                     0x0000000199416068 __CFRunLoopServiceMachPort
2   CoreFoundation                     0x0000000199411188 __CFRunLoopRun
3   CoreFoundation                     0x00000001994108bc CFRunLoopRunSpecific
4   Foundation                         0x0000000199750994 -[NSRunLoop(NSRunLoop) runMode:beforeDate:]
5   Foundation                         0x0000000199750874 -[NSRunLoop(NSRunLoop) runUntilDate:]
6   UIKitCore                          0x000000019d53e49c -[UIEventFetcher threadMain]
7   Foundation                         0x00000001998810b0 __NSThread__start__
8   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
9   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 5
0   libsystem_kernel.dylib             0x0000000199290c8c __psynch_cvwait
1   bundleidentifier                   0x00000001039c715c il2cpp::os::posix::PosixWaitObject::Wait(unsigned int, bool)
2   bundleidentifier                   0x00000001039a115c il2cpp::gc::FinalizerThread(void*)
3   bundleidentifier                   0x00000001039beb94 il2cpp::os::Thread::RunWrapper(void*)
4   bundleidentifier                   0x00000001039c0c18 il2cpp::os::ThreadImpl::ThreadStartWrapper(void*)
5   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
6   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 6
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 7
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 8
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 9
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 10
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 11
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 12
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 13
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 14
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 15
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 16
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 17
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 18
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 19
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 20
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 21
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 22
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 23
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 24
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 25
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 26
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 27
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x00000001033c0c88 ThreadedStreamBuffer::HandleOutOfBufferToReadFrom(ThreadedStreamBuffer::smile:ataOffsets)
3   bundleidentifier                   0x0000000103377e28 BatchDeleteStep2Threaded(void*)
4   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
5   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
6   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 28
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x00000001032b3ab0 AsyncReadManagerThreaded::ThreadEntry()
3   bundleidentifier                   0x00000001032b36d8 AsyncReadManagerThreaded::StaticThreadEntry(void*)
4   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
5   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
6   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 29
0   libsystem_kernel.dylib             0x000000019926f5f4 mach_msg_trap
1   CoreFoundation                     0x0000000199416068 __CFRunLoopServiceMachPort
2   CoreFoundation                     0x0000000199411188 __CFRunLoopRun
3   CoreFoundation                     0x00000001994108bc CFRunLoopRunSpecific
4   AVFAudio                           0x00000001a5e71e68 GenericRunLoopThread::Entry(void*)
5   AVFAudio                           0x00000001a5ec2df0 CAPThread::Entry(CAPThread*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 30
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   bundleidentifier                   0x0000000103961e04 FMOD::Thread::callback(void*)
2   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
3   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 31
0   libsystem_kernel.dylib             0x000000019926f5f4 mach_msg_trap
1   libEmbeddedSystemAUs.dylib         0x00000001b6c63794 AURemoteIO::IOThread::Entry(void*)
2   libAudioToolboxUtility.dylib       0x00000001a45024f8 CAPThread::Entry(CAPThread*)
3   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
4   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 32
0   libsystem_kernel.dylib             0x0000000199291238 __semwait_signal
1   libsystem_c.dylib                  0x00000001990fd51c usleep
2   bundleidentifier                   0x0000000103946910 FMOD_OS_Time_Sleep(unsigned int)
3   bundleidentifier                   0x0000000103961df0 FMOD::Thread::callback(void*)
4   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
5   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 33
0   libsystem_kernel.dylib             0x000000019926f5f4 mach_msg_trap
1   CoreFoundation                     0x0000000199416068 __CFRunLoopServiceMachPort
2   CoreFoundation                     0x0000000199411188 __CFRunLoopRun
3   CoreFoundation                     0x00000001994108bc CFRunLoopRunSpecific
4   CoreFoundation                     0x0000000199411608 CFRunLoopRun
5   CoreMotion                         0x00000001a5d3064c CLClientCreateIso6709Notation
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 34
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x0000000103384650 PreloadManager::Run()
3   bundleidentifier                   0x0000000103384604 PreloadManager::Run(void*)
4   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
5   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
6   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 35
0   libsystem_kernel.dylib             0x000000019926f630 semaphore_wait_trap
1   libdispatch.dylib                  0x00000001991384f0 _dispatch_semaphore_wait_slow
2   bundleidentifier                   0x000000010330548c CappedSemaphore::WaitForSignal()
3   bundleidentifier                   0x000000010334f7e8 JobQueue::ProcessJobs(void*)
4   bundleidentifier                   0x000000010334ec94 JobQueue::WorkLoop(void*)
5   bundleidentifier                   0x00000001033bfd08 Thread::RunThreadWrapper(void*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 36
0   libsystem_kernel.dylib             0x000000019926f5f4 mach_msg_trap
1   CoreFoundation                     0x0000000199416068 __CFRunLoopServiceMachPort
2   CoreFoundation                     0x0000000199411188 __CFRunLoopRun
3   CoreFoundation                     0x00000001994108bc CFRunLoopRunSpecific
4   CFNetwork                          0x000000019c68be68 
5   Foundation                         0x00000001998810b0 __NSThread__start__
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 37
0   libsystem_kernel.dylib             0x0000000199291a74 __workq_kernreturn
1   libsystem_pthread.dylib            0x00000001991b8ae0 start_wqthread

Thread 38
0   libsystem_kernel.dylib             0x0000000199290c8c __psynch_cvwait
1   libc++.1.dylib                     0x00000001992e27a8 std::__1::condition_variable::wait(std::__1::unique_lock<std::__1::mutex>&)
2   JavaScriptCore                     0x00000001a806e3fc void std::__1::condition_variable_any::wait<std::__1::unique_lock<bmalloc::Mutex> >(std::__1::unique_lock<bmalloc::Mutex>&)
3   JavaScriptCore                     0x00000001a8071dcc bmalloc::Scavenger::threadRunLoop()
4   JavaScriptCore                     0x00000001a8071ab4 bmalloc::Scavenger::Scavenger(std::__1::lock_guard<bmalloc::Mutex>&)
5   JavaScriptCore                     0x00000001a8072dc0 std::__1::__thread_specific_ptr<std::__1::__thread_struct>::set_pointer(std::__1::__thread_struct*)
6   libsystem_pthread.dylib            0x00000001991b51ec _pthread_start
7   libsystem_pthread.dylib            0x00000001991b8aec thread_start

Thread 39
0   libsystem_kernel.dylib             0x0000000199291a74 __workq_kernreturn
1   libsystem_pthread.dylib            0x00000001991b8ae0 start_wqthread

Thread 40
0   libsystem_kernel.dylib             0x0000000199291a74 __workq_kernreturn
1   libsystem_pthread.dylib            0x00000001991b8ae0 start_wqthread

Any insight would be greatly appreciated! Googling various keywords from the stack trace has not proven to be as helpful as I would have thought.

Getting this as well on builds from Xcode 11, using cloud build and 2018.4.14.

(Case 1209331) Native Crash - pthread kill