SIGSEGV error and crash when output device is not detected on startup

[neonchurch]

System Information

2019 Intel chip Macbook Pro, Sequoia 15.5

LMMS Version(s)

1.3.0-alpha.1.966+098f0ed

Most Recent Working Version

No response

Bug Summary

If you set the preferred output device to a device that might not be detected when not in use--in this case, Bluetooth headphones--LMMS crashes due to a segmentation fault. However, if you have this device connected again, it will launch.

Expected Behaviour

The program starting up normally and launching into the UI. LMMS crashes before loading the UI when it configures the audio devices.

Steps To Reproduce

1. With LMMS open, set the preferred output device to a device that is not in use all the time and might be absent next time. In this case, it was because I set it to use my Bluetooth headphones.
2. Close LMMS.
3. Turn off or remove the device that was in use as output (not sure if this occurs with all removable devices or only wireless).
4. Launch LMMS again. It will likely segfault and crash before launching the UI.

Logs

---

Translated Report (Full Report Below)

Process: lmms [4583]
Path: /Applications/LMMS-2.app/Contents/MacOS/lmms
Identifier: io.lmms
Version: (1.3.0-alpha.1.966+098f0ed)
Code Type: X86-64 (Native)
Parent Process: launchd [1]
User ID: 501

Date/Time: 2026-03-30 20:50:16.8776 -0500
OS Version: macOS 15.5 (24F74)
Report Version: 12
Bridge OS Version: 9.5 (22P5072)
Anonymous UUID: 41A63E69-2F10-4E17-BD57-D8F073CD1496

Sleep/Wake UUID: 8DDCFCCB-7EE0-454B-A4C7-C1429957D7D7

Time Awake Since Boot: 13000 seconds
Time Since Wake: 10373 seconds

System Integrity Protection: enabled

Crashed Thread: 19 com.apple.audio.IOThread.client

Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000
Exception Codes: 0x0000000000000001, 0x0000000000000000

Termination Reason: Namespace SIGNAL, Code 11 Segmentation fault: 11
Terminating Process: exc handler [4583]

VM Region Info: 0 is not in any region. Bytes before following region: 4464078848
REGION TYPE START - END [ VSIZE] PRT/MAX SHRMOD REGION DETAIL
UNUSED SPACE AT START
--->
__TEXT 10a147000-10a399000 [ 2376K] r-x/r-x SM=COW /Applications/LMMS-2.app/Contents/MacOS/lmms

Thread 0:: Dispatch queue: com.apple.main-thread
0 libsystem_malloc.dylib 0x7ff8057d332f nanov2_malloc_type + 117
1 QtCore 0x10b8a86a9 QArrayData::allocate(unsigned long, unsigned long, unsigned long, QFlagsQArrayData::AllocationOption) + 249
2 QtCore 0x10b92a0c4 QString::reallocData(unsigned int, bool) + 100
3 QtCore 0x10b92a038 QString::resize(int) + 88
4 QtCore 0x10b9b8d1e 0x10b87a000 + 1305886
5 QtCore 0x10b9b85d2 0x10b87a000 + 1304018
6 QtCore 0x10b9b95e4 0x10b87a000 + 1308132
7 QtCore 0x10b9bbf7d 0x10b87a000 + 1318781
8 QtCore 0x10b9a5a9f QFile::open(QFlagsQIODevice::OpenModeFlag) + 95
9 QtGui 0x10bf7cd33 0x10bed7000 + 679219
10 QtGui 0x10bf7e63f QImageReader::format() const + 47
11 QtGui 0x10bf9845f QPixmapIconEngine::addFile(QString const&, QSize const&, QIcon::Mode, QIcon::State) + 239
12 QtGui 0x10bf99b15 QIcon::addFile(QString const&, QSize const&, QIcon::Mode, QIcon::State) + 517
13 QtWidgets 0x10b369f9c 0x10b2ca000 + 655260
14 QtWidgets 0x10b368793 QCommonStyle::standardIcon(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const + 4323
15 QtWidgets 0x10b3b4fe2 QFusionStyle::standardIcon(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const + 114
16 QtWidgets 0x10b36d0ec QProxyStyle::standardIcon(QStyle::StandardPixmap, QStyleOption const*, QWidget const*) const + 76
17 QtWidgets 0x10b3854f5 0x10b2ca000 + 767221
18 QtWidgets 0x10b4b833a 0x10b2ca000 + 2024250
19 QtCore 0x10ba7dea4 0x10b87a000 + 2113188
20 QtWidgets 0x10b4a58d0 QToolBar::setOrientation(Qt::Orientation) + 144
21 lmms 0x10a28abf8 lmms::gui::SideBar::SideBar(Qt::Orientation, QWidget*) + 88
22 lmms 0x10a262f7d lmms::gui::MainWindow::MainWindow() + 381
23 lmms 0x10a25b23a lmms::gui::GuiApplication::GuiApplication() + 1834
24 lmms 0x10a14fb23 main + 10179
25 dyld 0x7ff805600530 0x7ff8055fa000 + 25904

Thread 1:
0 libsystem_pthread.dylib 0x7ff8059a1834 start_wqthread + 0

Thread 2:
0 libsystem_pthread.dylib 0x7ff8059a1834 start_wqthread + 0

Thread 3:
0 libsystem_pthread.dylib 0x7ff8059a1834 start_wqthread + 0

Thread 4:: com.apple.CFSocket.private
0 libsystem_kernel.dylib 0x7ff80596c9fe __select + 10
1 CoreFoundation 0x7ff805ab326c __CFSocketManager + 671
2 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
3 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 5:
0 libsystem_pthread.dylib 0x7ff8059a1834 start_wqthread + 0

Thread 6:: com.apple.NSEventThread
0 libsystem_kernel.dylib 0x7ff805963b4a mach_msg2_trap + 10
1 libsystem_kernel.dylib 0x7ff805972704 mach_msg2_internal + 83
2 libsystem_kernel.dylib 0x7ff80596abc3 mach_msg_overwrite + 574
3 libsystem_kernel.dylib 0x7ff805963e3b mach_msg + 19
4 CoreFoundation 0x7ff805a8ed42 __CFRunLoopServiceMachPort + 145
5 CoreFoundation 0x7ff805a8d78f __CFRunLoopRun + 1430
6 CoreFoundation 0x7ff805a8cbc2 CFRunLoopRunSpecific + 536
7 AppKit 0x7ff809648a2f _NSEventThread + 127
8 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
9 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 7:: lmms::AudioEngineWorkerThread
0 libsystem_kernel.dylib 0x7ff805965e72 __psynch_mutexwait + 10
1 libsystem_pthread.dylib 0x7ff8059a378c _pthread_mutex_firstfit_lock_wait + 78
2 libsystem_pthread.dylib 0x7ff8059a15a1 _pthread_mutex_firstfit_lock_slow + 217
3 libsystem_pthread.dylib 0x7ff8059a630c _pthread_cond_wait + 1134
4 QtCore 0x10b8a313b 0x10b87a000 + 168251
5 QtCore 0x10b8a30b3 QWaitCondition::wait(QMutex*, QDeadlineTimer) + 83
6 lmms 0x10a17b80d lmms::AudioEngineWorkerThread::run() + 173
7 QtCore 0x10b89b303 0x10b87a000 + 135939
8 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
9 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 8:: lmms::AudioEngineWorkerThread
0 libsystem_kernel.dylib 0x7ff805965e72 __psynch_mutexwait + 10
1 libsystem_pthread.dylib 0x7ff8059a378c _pthread_mutex_firstfit_lock_wait + 78
2 libsystem_pthread.dylib 0x7ff8059a15a1 _pthread_mutex_firstfit_lock_slow + 217
3 libsystem_pthread.dylib 0x7ff8059a630c _pthread_cond_wait + 1134
4 QtCore 0x10b8a313b 0x10b87a000 + 168251
5 QtCore 0x10b8a30b3 QWaitCondition::wait(QMutex*, QDeadlineTimer) + 83
6 lmms 0x10a17b80d lmms::AudioEngineWorkerThread::run() + 173
7 QtCore 0x10b89b303 0x10b87a000 + 135939
8 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
9 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 9:: lmms::AudioEngineWorkerThread
0 libsystem_kernel.dylib 0x7ff8059666f6 __psynch_cvwait + 10
1 libsystem_pthread.dylib 0x7ff8059a627a _pthread_cond_wait + 988
2 QtCore 0x10b8a313b 0x10b87a000 + 168251
3 QtCore 0x10b8a30b3 QWaitCondition::wait(QMutex*, QDeadlineTimer) + 83
4 lmms 0x10a17b80d lmms::AudioEngineWorkerThread::run() + 173
5 QtCore 0x10b89b303 0x10b87a000 + 135939
6 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
7 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 10:: lmms::AudioEngineWorkerThread
0 libsystem_kernel.dylib 0x7ff805965e72 __psynch_mutexwait + 10
1 libsystem_pthread.dylib 0x7ff8059a378c _pthread_mutex_firstfit_lock_wait + 78
2 libsystem_pthread.dylib 0x7ff8059a15a1 _pthread_mutex_firstfit_lock_slow + 217
3 libsystem_pthread.dylib 0x7ff8059a630c _pthread_cond_wait + 1134
4 QtCore 0x10b8a313b 0x10b87a000 + 168251
5 QtCore 0x10b8a30b3 QWaitCondition::wait(QMutex*, QDeadlineTimer) + 83
6 lmms 0x10a17b80d lmms::AudioEngineWorkerThread::run() + 173
7 QtCore 0x10b89b303 0x10b87a000 + 135939
8 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
9 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 11:: lmms::AudioEngineWorkerThread
0 libsystem_kernel.dylib 0x7ff8059666f6 __psynch_cvwait + 10
1 libsystem_pthread.dylib 0x7ff8059a627a _pthread_cond_wait + 988
2 QtCore 0x10b8a313b 0x10b87a000 + 168251
3 QtCore 0x10b8a30b3 QWaitCondition::wait(QMutex*, QDeadlineTimer) + 83
4 lmms 0x10a17b80d lmms::AudioEngineWorkerThread::run() + 173
5 QtCore 0x10b89b303 0x10b87a000 + 135939
6 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
7 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 12:: lmms::AudioEngineWorkerThread
0 libsystem_kernel.dylib 0x7ff8059666f6 __psynch_cvwait + 10
1 libsystem_pthread.dylib 0x7ff8059a627a _pthread_cond_wait + 988
2 QtCore 0x10b8a313b 0x10b87a000 + 168251
3 QtCore 0x10b8a30b3 QWaitCondition::wait(QMutex*, QDeadlineTimer) + 83
4 lmms 0x10a17b80d lmms::AudioEngineWorkerThread::run() + 173
5 QtCore 0x10b89b303 0x10b87a000 + 135939
6 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
7 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 13:: lmms::AudioEngineWorkerThread
0 libsystem_kernel.dylib 0x7ff805965e72 __psynch_mutexwait + 10
1 libsystem_pthread.dylib 0x7ff8059a378c _pthread_mutex_firstfit_lock_wait + 78
2 libsystem_pthread.dylib 0x7ff8059a15a1 _pthread_mutex_firstfit_lock_slow + 217
3 libsystem_pthread.dylib 0x7ff8059a630c _pthread_cond_wait + 1134
4 QtCore 0x10b8a313b 0x10b87a000 + 168251
5 QtCore 0x10b8a30b3 QWaitCondition::wait(QMutex*, QDeadlineTimer) + 83
6 lmms 0x10a17b80d lmms::AudioEngineWorkerThread::run() + 173
7 QtCore 0x10b89b303 0x10b87a000 + 135939
8 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
9 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 14:: caulk.messenger.shared:17
0 libsystem_kernel.dylib 0x7ff805963ac6 semaphore_wait_trap + 10
1 caulk 0x7ff811088a42 caulk::semaphore::timed_wait(double) + 158
2 caulk 0x7ff811088964 caulk::concurrent::details::worker_thread::run() + 30
3 caulk 0x7ff8110886a8 void* caulk::thread_proxy<std::__1::tuple<caulk::thread::attributes, void (caulk::concurrent::details::worker_thread::)(), std::__1::tuplecaulk::concurrent::details::worker_thread*>>(void) + 41
4 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
5 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 15:: caulk.messenger.shared:high
0 libsystem_kernel.dylib 0x7ff805963ac6 semaphore_wait_trap + 10
1 caulk 0x7ff811088a42 caulk::semaphore::timed_wait(double) + 158
2 caulk 0x7ff811088964 caulk::concurrent::details::worker_thread::run() + 30
3 caulk 0x7ff8110886a8 void* caulk::thread_proxy<std::__1::tuple<caulk::thread::attributes, void (caulk::concurrent::details::worker_thread::)(), std::__1::tuplecaulk::concurrent::details::worker_thread*>>(void) + 41
4 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
5 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 16:: caulk::deferred_logger
0 libsystem_kernel.dylib 0x7ff805963ac6 semaphore_wait_trap + 10
1 caulk 0x7ff811088a42 caulk::semaphore::timed_wait(double) + 158
2 caulk 0x7ff811088964 caulk::concurrent::details::worker_thread::run() + 30
3 caulk 0x7ff8110886a8 void* caulk::thread_proxy<std::__1::tuple<caulk::thread::attributes, void (caulk::concurrent::details::worker_thread::)(), std::__1::tuplecaulk::concurrent::details::worker_thread*>>(void) + 41
4 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
5 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 17:
0 libsystem_kernel.dylib 0x7ff805963b4a mach_msg2_trap + 10
1 libsystem_kernel.dylib 0x7ff805972704 mach_msg2_internal + 83
2 libsystem_kernel.dylib 0x7ff80596abc3 mach_msg_overwrite + 574
3 libsystem_kernel.dylib 0x7ff805963e3b mach_msg + 19
4 CoreMIDI 0x7ff822ae9674 XServerMachPort::ReceiveMessage(int&, void*, int&) + 98
5 CoreMIDI 0x7ff822b09d92 MIDIProcess::MIDIInPortThread::Run() + 104
6 CoreMIDI 0x7ff822aff4dc CADeprecated::XThread::RunHelper(void*) + 10
7 CoreMIDI 0x7ff822b09503 CADeprecated::CAPThread::Entry(CADeprecated::CAPThread*) + 77
8 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
9 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 18:: AudioEngine::fifoWriter
0 libsystem_kernel.dylib 0x7ff80596670e __psynch_cvbroad + 10
1 libsystem_pthread.dylib 0x7ff8059a1c43 pthread_cond_broadcast + 766
2 QtCore 0x10b8a2f67 QWaitCondition::wakeAll() + 39
3 lmms 0x10a17b647 lmms::AudioEngineWorkerThread::startAndWaitForJobs() + 23
4 lmms 0x10a1794cb lmms::AudioEngine::renderStageInstruments() + 139
5 lmms 0x10a1798eb lmms::AudioEngine::renderNextBuffer() + 75
6 lmms 0x10a17a850 lmms::AudioEngine::fifoWriter::run() + 240
7 QtCore 0x10b89b303 0x10b87a000 + 135939
8 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
9 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 19 Crashed:: com.apple.audio.IOThread.client
0 lmms 0x10a2242e7 lmms::AudioPortAudio::processCallback(void const*, void*, unsigned long, PaStreamCallbackTimeInfo const*, unsigned long, void*) + 183
1 libportaudio.2.dylib 0x10ac937e5 AdaptingInputOnlyProcess + 419
2 libportaudio.2.dylib 0x10ac92d1a PaUtil_EndBufferProcessing + 603
3 libportaudio.2.dylib 0x10ac97cdd AudioIOProc + 2133
4 CoreAudio 0x11c94ceed 0x11c941000 + 48877
5 CoreAudio 0x7ff80842adf1 HALC_ProxyIOContext::IOWorkLoop() + 13017
6 CoreAudio 0x7ff808427387 invocation function for block in HALC_ProxyIOContext::HALC_ProxyIOContext(unsigned int, unsigned int) + 141
7 CoreAudio 0x7ff8085d646f HALC_IOThread::Entry(void*) + 73
8 libsystem_pthread.dylib 0x7ff8059a5df1 _pthread_start + 99
9 libsystem_pthread.dylib 0x7ff8059a1857 thread_start + 15

Thread 19 crashed with X86 Thread State (64-bit):
rax: 0x0000000000000000 rbx: 0x0000000000000100 rcx: 0x00007fcecc0b7800 rdx: 0x0000000000000000
rdi: 0x00000000c1786fc4 rsi: 0x000000010ad7f600 rbp: 0x0000700001b779f0 rsp: 0x0000700001b779c0
r8: 0x00007fcecd0b7800 r9: 0x00007fcecd083400 r10: 0x00007fcecd007f00 r11: 0x00007fcecd008101
r12: 0x0000000000000000 r13: 0x0000000000000000 r14: 0x0000000000000000 r15: 0x0000600003495ff0
rip: 0x000000010a2242e7 rfl: 0x0000000000010206 cr2: 0x0000000000000000

Logical CPU: 2
Error Code: 0x00000006 (no mapping for user data write)
Trap Number: 14

Thread 19 instruction stream:
57 10 eb 22 0f 1f 44 00-00 89 45 d4 49 8b 77 48 W.."..D...E.I.wH
4c 89 ff e8 01 87 ff ff-41 0f b7 57 10 48 85 c0 L.......A..W.H..
0f 84 7c 00 00 00 49 8b-4f 48 49 8b 47 60 f3 0f ..|...I.OHI.G`..
10 04 c1 66 83 fa 01 75-20 f3 0f 58 44 c1 04 f3 ...f...u ..XD...
0f 59 05 92 57 16 00 f3-43 0f 11 04 ae eb 24 66 .Y..W...C.....$f
2e 0f 1f 84 00 00 00 00-00 0f b7 d2 49 0f af d5 ............I...
[f3]41 0f 11 04 96 f3 0f-10 44 c1 04 f3 41 0f 11 .A.......D...A.. <==
44 96 04 48 ff c0 49 8b-7f 50 48 29 cf 48 c1 ff D..H..I..PH).H..
03 48 89 c1 48 09 f9 48-c1 e9 20 0f 85 48 ff ff .H..H..H.. ..H..
ff 31 d2 f7 f7 e9 44 ff-ff ff 31 c0 eb 30 31 c0 .1....D...1..01.
eb 3a 0f b7 c2 48 89 d9-4c 29 e9 48 0f af c8 48 .:...H..L).H...H
85 c9 7e 17 49 8d 34 9c-4c 0f af e0 4d 29 e6 48 ..~.I.4.L...M).H

Screenshots / Minimum Reproducible Project

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