#0  asyncDiscardEvent (event=0x0) at ../../Programs/async_event.c:147
  142:   return NULL;
  143: }
  144: 
  145: void
  146: asyncDiscardEvent (AsyncEvent *event) {
  147:   asyncCancelRequest(event->monitorHandle);
  148: 
  149:   closeFileDescriptor(event->pipeInput);
  150:   closeFileDescriptor(event->pipeOutput);
  151: 
  152: #ifdef __MINGW32__
#1  runSpeechDriverThread (argument=0x5642f4c2b890) at ../../Programs/spk_thread.c:842
  837:       stopSpeechDriver(sdt);
  838:     } else {
  839:       logMessage(LOG_CATEGORY(SPEECH_EVENTS), "driver construction failure");
  840:     }
  841: 
  842:     asyncDiscardEvent(sdt->requestEvent);
  843:     sdt->requestEvent = NULL;
  844:   } else {
  845:     logMessage(LOG_CATEGORY(SPEECH_EVENTS), "request event construction failure");
  846:   }
  847: 
#2  0x00005642f3fb00cd in runThread (argument=0x5642f4c2bb80) at ../../Programs/thread.c:46
  41: runThread (void *argument) {
  42:   RunThreadArgument *run = argument;
  43: 
  44:   setThreadName(run->name);
  45:   logMessage(LOG_CATEGORY(ASYNC_EVENTS), "thread starting: %s", run->name);
  46:   void *result = run->function(run->argument);
  47:   logMessage(LOG_CATEGORY(ASYNC_EVENTS), "thread finished: %s", run->name);
  48: 
  49:   free(run);
  50:   return result;
  51: }
#3  0x00007f91eb78fb43 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
  [Error: pthread_create.c was not found in source tree]
#4  0x00007f91eb821a00 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
  [Error: clone3.S was not found in source tree]