Here's one with the abort/sigsegv handler fixed and verbose messages enabled:

Fri Apr 20 11:39:58 2012: Client 'system' with PID 0 is out
Fri Apr 20 11:39:58 2012: Jack: jack_client_close
Fri Apr 20 11:39:58 2012: Jack: JackClient::Close ref = 2
Fri Apr 20 11:39:58 2012: Jack: JackClient::Deactivate
Fri Apr 20 11:39:58 2012: Jack: JackEngine::ClientCloseAux ref = 2
Fri Apr 20 11:39:58 2012: Jack: JackGraphManager::RemoveAllPorts ref = 2
Fri Apr 20 11:39:58 2012: Jack: JackProcessSync::TimedWait time out = 1000000
Fri Apr 20 11:39:58 2012: Jack: fPollTable i = 1 fd = 11
Fri Apr 20 11:39:58 2012: Jack: JackRequest::Notification
Fri Apr 20 11:39:58 2012: Jack: JackProcessSync::TimedWait finished delta = 19398.0
Fri Apr 20 11:39:58 2012: Jack: JackDriver::ClientNotify ref = 2 driver = system name = dbusapi notify = 1
Fri Apr 20 11:39:58 2012: Jack: JackDriver::ClientNotify ref = 2 driver = freewheel name = dbusapi notify = 1
Fri Apr 20 11:39:58 2012: Jack: JackPosixSemaphore::Destroy name = jack_sem.1000_default_dbusapi
Fri Apr 20 11:39:58 2012: Jack: jack_client_close res = 0
Fri Apr 20 11:39:58 2012: Jack: JackServer::Stop
Fri Apr 20 11:39:58 2012: Jack: JackPosixThread::Kill
Fri Apr 20 11:39:58 2012: ERROR: Abort!
Fri Apr 20 11:39:58 2012: ERROR: info.si_signo = 6
Fri Apr 20 11:39:58 2012: ERROR: info.si_errno = 0
Fri Apr 20 11:39:58 2012: ERROR: info.si_code  = -6 (unknown)
Fri Apr 20 11:39:58 2012: ERROR: info.si_addr  = 0x3e800000e09
Fri Apr 20 11:39:58 2012: ERROR: reg[00]       = 0x00007f43d7984aa0
Fri Apr 20 11:39:58 2012: ERROR: reg[01]       = 0x00007f43d8897700
Fri Apr 20 11:39:58 2012: ERROR: reg[02]       = 0x0000000000000008
Fri Apr 20 11:39:58 2012: ERROR: reg[03]       = 0x0000000000000206
Fri Apr 20 11:39:58 2012: ERROR: reg[04]       = 0x00007f43d8895420
Fri Apr 20 11:39:58 2012: ERROR: reg[05]       = 0x0000000000000000
Fri Apr 20 11:39:58 2012: ERROR: reg[06]       = 0x0000000000000000
Fri Apr 20 11:39:58 2012: ERROR: reg[07]       = 0x00007f43d82a3211
Fri Apr 20 11:39:58 2012: ERROR: reg[08]       = 0x0000000000000e09
Fri Apr 20 11:39:58 2012: ERROR: reg[09]       = 0x0000000000000e34
Fri Apr 20 11:39:58 2012: ERROR: reg[10]       = 0x00007f43d8897d70
Fri Apr 20 11:39:58 2012: ERROR: reg[11]       = 0x0000000000000008
Fri Apr 20 11:39:58 2012: ERROR: reg[12]       = 0x0000000000000006
Fri Apr 20 11:39:58 2012: ERROR: reg[13]       = 0x0000000000000000
Fri Apr 20 11:39:58 2012: ERROR: reg[14]       = 0xffffffffffffffff
Fri Apr 20 11:39:58 2012: ERROR: reg[15]       = 0x00007f43d8894f18
Fri Apr 20 11:39:58 2012: ERROR: reg[16]       = 0x00007f43d7602445
Fri Apr 20 11:39:58 2012: ERROR: reg[17]       = 0x0000000000000206
Fri Apr 20 11:39:58 2012: ERROR: reg[18]       = 0x0000000000000033
Fri Apr 20 11:39:58 2012: ERROR: reg[19]       = 0x0000000000000000
Fri Apr 20 11:39:58 2012: ERROR: reg[20]       = 0x0000000000000000
Fri Apr 20 11:39:58 2012: ERROR: reg[21]       = 0x0000000080005a07
Fri Apr 20 11:39:58 2012: ERROR: reg[22]       = 0x0000000000000000
Fri Apr 20 11:39:58 2012: ERROR: Stack trace:
Fri Apr 20 11:39:58 2012: ERROR:  1: 0x7f43d7602445 <gsignal+53> (/lib/x86_64-linux-gnu/libc.so.6)
Fri Apr 20 11:39:58 2012: ERROR: End of stack trace