libc++abi: terminating due to uncaught exception of type std::__1::system_error: thread::join failed: Invalid argument
Process 6913 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
    frame #0: 0x000000018748e0dc libsystem_kernel.dylib`__pthread_kill + 8
libsystem_kernel.dylib`:
->  0x18748e0dc <+8>:  b.lo   0x18748e0fc               ; <+40>
    0x18748e0e0 <+12>: pacibsp
    0x18748e0e4 <+16>: stp    x29, x30, [sp, #-0x10]!
    0x18748e0e8 <+20>: mov    x29, sp
Target 0: (exult) stopped.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
  * frame #0: 0x000000018748e0dc libsystem_kernel.dylib`__pthread_kill + 8
    frame #1: 0x00000001874c5cc0 libsystem_pthread.dylib`pthread_kill + 288
    frame #2: 0x00000001873d1a40 libsystem_c.dylib`abort + 180
    frame #3: 0x000000018747d070 libc++abi.dylib`abort_message + 132
    frame #4: 0x000000018746d110 libc++abi.dylib`demangling_terminate_handler() + 320
    frame #5: 0x000000018711399c libobjc.A.dylib`_objc_terminate() + 160
    frame #6: 0x000000018747c434 libc++abi.dylib`std::__terminate(void (*)()) + 16
    frame #7: 0x000000018747f520 libc++abi.dylib`__cxxabiv1::failed_throw(__cxxabiv1::__cxa_exception*) + 88
    frame #8: 0x000000018747f464 libc++abi.dylib`__cxa_throw + 308
    frame #9: 0x00000001873fb6b8 libc++.1.dylib`std::__1::__throw_system_error(int, char const*) + 100
    frame #10: 0x00000001873fb75c libc++.1.dylib`std::__1::thread::join() + 72
    frame #11: 0x000000010017dccc exult`LowLevelMidiDriver::do_quit_thread(this=0x000000012880d800, detach=false) at LowLevelMidiDriver.cpp:638:12
    frame #12: 0x000000010017e304 exult`LowLevelMidiDriver::destroyMidiDriver(this=0x000000012880d800) at LowLevelMidiDriver.cpp:251:2
    frame #13: 0x00000001001642a8 exult`MyMidiPlayer::set_midi_driver(this=0x000060000243bba0, desired_driver="CoreMidi", use_oggs=false) at Midi.cc:552:17
    frame #14: 0x000000010038ebf4 exult`AudioOptions_gump::save_settings(this=0x00000001544044e0) at AudioOptions_gump.cc:578:9
    frame #15: 0x000000010038e4c8 exult`AudioOptions_gump::close(this=0x00000001544044e0) at AudioOptions_gump.cc:70:2
    frame #16: 0x0000000100394dbc exult`CallbackButtonBase<AudioOptions_gump, Text_button>::activate(this=0x000060000242e400, button=1) at Gump_button.h:132:3
    frame #17: 0x0000000100392dec exult`AudioOptions_gump::mouse_up(this=0x00000001544044e0, mx=279, my=284, button=1) at AudioOptions_gump.cc:742:17
    frame #18: 0x00000001003a9998 exult`Gump_manager::handle_modal_gump_event(this=0x0000600000023e20, gump=0x00000001544044e0, event=0x000000016fdfdd30) at Gump_manager.cc:546:10
    frame #19: 0x00000001003aa400 exult`Gump_manager::do_modal_gump(this=0x0000600000023e20, gump=0x00000001544044e0, shape=hand, paint=0x0000000000000000) at Gump_manager.cc:782:15
    frame #20: 0x000000010036f974 exult`Gamemenu_gump::audio_options(this=0x000000016fdfe028) at Gamemenu_gump.cc:133:11
    frame #21: 0x0000000100370994 exult`CallbackButtonBase<Gamemenu_gump, Text_button>::activate(this=0x0000600002409680, button=1) at Gump_button.h:132:3
    frame #22: 0x00000001003700a8 exult`Gamemenu_gump::mouse_up(this=0x000000016fdfe028, mx=314, my=177, button=1) at Gamemenu_gump.cc:196:12
    frame #23: 0x00000001003a9998 exult`Gump_manager::handle_modal_gump_event(this=0x0000600000023e20, gump=0x000000016fdfe028, event=0x000000016fdfdfb0) at Gump_manager.cc:546:10
    frame #24: 0x00000001003aa400 exult`Gump_manager::do_modal_gump(this=0x0000600000023e20, gump=0x000000016fdfe028, shape=hand, paint=0x0000000000000000) at Gump_manager.cc:782:15
    frame #25: 0x0000000100370124 exult`Gamemenu_gump::do_exult_menu() at Gamemenu_gump.cc:208:47
    frame #26: 0x0000000100094cdc exult`ExultMenu::setup(this=0x000000016fdfe738) at exultmenu.cc:176:2
    frame #27: 0x00000001000972cc exult`ExultMenu::run(this=0x000000016fdfe738) at exultmenu.cc:481:4
    frame #28: 0x000000010008a594 exult`Init() at exult.cc:938:25
    frame #29: 0x0000000100084e90 exult`exult_main(runpath="/Users/Dominus/code/snapshots/exult/exult") at exult.cc:645:2
    frame #30: 0x0000000100083684 exult`main(argc=1, argv=0x000000016fdff4c0) at exult.cc:458:12
    frame #31: 0x00000001871450e0 dyld`start + 2360