Help understanding very cryptic crash report from TestFlight - "mach_msg2_trap"

Here's thread 2 from crashlog.crash:

Thread 2 Crashed:
0   ???                           	0x00000000b71b8091 0x0 + 3072032913
1   libswift_Concurrency.dylib    	0x00000002276b9828 (anonymous namespace)::ProcessOutOfLineJob::process(swift::Job*) + 884 (Actor.cpp:1323)
2   libswift_Concurrency.dylib    	0x00000002276b7eb8 swift::runJobInEstablishedExecutorContext(swift::Job*) + 556 (Actor.cpp:229)
3   libswift_Concurrency.dylib    	0x00000002276b8cd0 swift_job_runImpl(swift::Job*, swift::ExecutorRef) + 72 (Actor.cpp:1563)
4   libdispatch.dylib             	0x0000000199e15e98 _dispatch_root_queue_drain + 396 (queue.c:7051)
5   libdispatch.dylib             	0x0000000199e166c0 _dispatch_worker_thread2 + 164 (queue.c:7119)
6   libsystem_pthread.dylib       	0x0000000199fb0038 _pthread_wqthread + 228 (pthread.c:2631)
7   libsystem_pthread.dylib       	0x0000000199faed94 start_wqthread + 8

and a better screenshot just in case:

Thank you very much for the help!