~Audio:  about to quit subsystem
Destroying AudioMixer...
Destroying MidiDriver...
Assertion failed: (self != nullptr), function get_ptr, file Audio.cc, line 231.
Process 78442 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
    frame #0: 0x00007fff67ffc33a libsystem_kernel.dylib`__pthread_kill + 10
libsystem_kernel.dylib`__pthread_kill:
->  0x7fff67ffc33a <+10>: jae    0x7fff67ffc344            ; <+20>
    0x7fff67ffc33c <+12>: movq   %rax, %rdi
    0x7fff67ffc33f <+15>: jmp    0x7fff67ff6629            ; cerror_nocancel
    0x7fff67ffc344 <+20>: retq
Target 0: (exult) stopped.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
  * frame #0: 0x00007fff67ffc33a libsystem_kernel.dylib`__pthread_kill + 10
    frame #1: 0x00007fff680b8e60 libsystem_pthread.dylib`pthread_kill + 430
    frame #2: 0x00007fff67f83808 libsystem_c.dylib`abort + 120
    frame #3: 0x00007fff67f82ac6 libsystem_c.dylib`__assert_rtn + 314
    frame #4: 0x000000010028eaf3 exult`Audio::get_ptr() (.cold.1) + 35
    frame #5: 0x00000001000d1627 exult`Audio::get_ptr() at Audio.cc:231:2 [opt]
    frame #6: 0x00000001000d7d55 exult`MyMidiPlayer::init_device(this=0x00000001202b03e0, timbre_load=false) at Midi.cc:507:15 [opt]
    frame #7: 0x00000001000d828c exult`MyMidiPlayer::stop_music(this=0x00000001202b03e0) at Midi.cc:400:38 [opt]
    frame #8: 0x00000001000debf9 exult`Pentagram::AudioMixer::closeMidiOutput(this=0x000000010124a7c0) at AudioMixer.cc:333:8 [opt]
    frame #9: 0x00000001000deb6d exult`Pentagram::AudioMixer::~AudioMixer(this=0x000000010124a7c0) at AudioMixer.cc:119:2 [opt]
    frame #10: 0x00000001000d6733 exult`std::__1::default_delete<Pentagram::AudioMixer>::operator(this=<unavailable>, __ptr=0x000000010124a7c0)(Pentagram::AudioMixer*) const at memory:2338:5 [opt]
    frame #11: 0x00000001000d25a3 exult`Audio::~Audio(this=0x00000001202ab440) at Audio.cc:410:1 [opt]
    frame #12: 0x00000001000d15da exult`Audio::Destroy() at Audio.cc:223:2 [opt]
    frame #13: 0x000000010004837e exult`Play() at exult.cc:916:2 [opt]
    frame #14: 0x00000001000447ee exult`exult_main(runpath=<unavailable>) at exult.cc:596:15 [opt]
    frame #15: 0x000000010004379a exult`main(argc=<unavailable>, argv=0x00007ffeefbff720) at exult.cc:392:12 [opt]
    frame #16: 0x0000000100000f34 exult`start + 52