On the MacIntel build I made I get this when sending a command to the [shell] object:

Pd: signal 6 closing audio... closing MIDI... ... done.

This actually registers as a crash in the crash logs but Pd keeps running. I use the -noaudio -nomidi flags but that doesn't seem to turn audio and MIDI off fully.

Here's one of the thousands of crash reports:

Thread 0 Crashed: 0 libSystem.B.dylib 0x900252a9 restore_sem_to_pool + 61 1 libSystem.B.dylib 0x90001f5c pthread_mutex_lock + 518 2 com.apple.audio.CoreAudio 0x9144297c CAMutex::Lock() + 58 3 com.apple.audio.CoreAudio 0x914587cd IOA_Device::StartCommandExecution(void**) + 41 4 com.apple.audio.CoreAudio 0x914586a3 HP_Device::ExecuteCommand(HP_Command*) + 61 5 com.apple.audio.CoreAudio 0x9145860d HP_Device::Do_StopAllIOProcs() + 65 6 com.apple.audio.CoreAudio 0x9145859b IOA_SingleDeviceManager::StopAllIOProcs() + 47 7 com.apple.audio.CoreAudio 0x91458551 IOA_PlugIn::StopAllIOProcs() + 21 8 com.apple.audio.CoreAudio 0x914584ea IOA_PlugIn::Teardown() + 242 9 com.apple.audio.CoreAudio 0x914583c0 HP_PlugIn_Teardown(AudioHardwarePlugInInterface**) + 78 10 com.apple.audio.CoreAudio 0x91458365 HALPlugIn::Teardown() + 21 11 com.apple.audio.CoreAudio 0x91458198 HALPlugInManagement::Teardown() + 240 12 com.apple.audio.CoreAudio 0x9145809f HALSystem::TeardownDevices() + 11 13 com.apple.audio.CoreAudio 0x9145803c HALSystem::AtExitHandler() + 124 14 com.apple.audio.CoreAudio 0x91457f9b HALAtExit::AtExitHandler() + 79 15 libSystem.B.dylib 0x90010d0c __cxa_finalize + 237 16 libSystem.B.dylib 0x90010c08 exit + 24 17 shell.pd_darwin 0x0ad44d4c shell_anything + 745 (bundle1.s:110) 18 pd 0x00037a63 pd_typedmess + 340 (m_class.c:754) 19 pd 0x00038fbf outlet_anything + 78 (m_obj.c:386) 20 pd 0x00037a63 pd_typedmess + 340 (m_class.c:754) 21 pd 0x0003af58 binbuf_eval + 931 (m_binbuf.c:574) 22 pd 0x00008f37 message_bang + 43 (g_text.c:294) 23 pd 0x00038d24 outlet_bang + 56 (m_obj.c:327) 24 pd 0x0003ec01 sched_tick + 100 (m_sched.c:356) 25 pd 0x0003f00a m_scheduler + 898 (m_sched.c:460) 26 pd 0x00040bcb sys_main + 1239 (s_main.c:294) 27 pd 0x00001f8a _start + 228 (crt.c:272) 28 pd 0x00001ea5 start + 41

cgc