midiobserve example crash on Ubuntu 24.04

[obook]

Hello.

I am testing the midiobserve program on Ubuntu 24.04 and it crashes when plugging a USB MIDI keyboard (Arturia Keylab 61).

Here is the gdb output with midiobserve compiled in DEBUG :

$ gdb ./midiobserve 
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Reading symbols from ./midiobserve...
(gdb) run
Starting program: /home/user/Dev/MIDI/libremidi/build_debug/midiobserve 

This GDB supports auto-downloading debuginfo from the following URLs:
  <https://debuginfod.ubuntu.com>
Enable debuginfod for this session? (y or [n]) 
Debuginfod has been disabled.
To make this setting permanent, add 'set debuginfod enabled off' to .gdbinit.
warning: could not find '.gnu_debugaltlink' file for /lib/x86_64-linux-gnu/libjack.so.0
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Displaying ports for: ALSA (sequencer)
warning: could not find '.gnu_debugaltlink' file for /lib/x86_64-linux-gnu/libcap.so.2
warning: could not find '.gnu_debugaltlink' file for /lib/x86_64-linux-gnu/alsa-lib/libasound_module_conf_pulse.so
warning: could not find '.gnu_debugaltlink' file for /lib/x86_64-linux-gnu/libpulse.so.0
warning: could not find '.gnu_debugaltlink' file for /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-16.1.so
[New Thread 0x7ffff6c006c0 (LWP 26436)]


Displaying ports for: ALSA (raw)
[New Thread 0x7ffff62006c0 (LWP 26437)]


Displaying ports for: JACK
[New Thread 0x7ffff6c896c0 (LWP 26438)]
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
[Thread 0x7ffff6c896c0 (LWP 26438) exited]
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock


Displaying ports for: PipeWire
warning: could not find '.gnu_debugaltlink' file for /usr/lib/x86_64-linux-gnu/spa-0.2/support/libspa-support.so
warning: could not find '.gnu_debugaltlink' file for /usr/lib/x86_64-linux-gnu/spa-0.2/support/libspa-journal.so
warning: could not find '.gnu_debugaltlink' file for /usr/lib/x86_64-linux-gnu/spa-0.2/support/libspa-dbus.so
warning: could not find '.gnu_debugaltlink' file for /usr/lib/x86_64-linux-gnu/pipewire-0.3/libpipewire-module-protocol-native.so
warning: could not find '.gnu_debugaltlink' file for /usr/lib/x86_64-linux-gnu/pipewire-0.3/libpipewire-module-client-node.so
warning: could not find '.gnu_debugaltlink' file for /usr/lib/x86_64-linux-gnu/pipewire-0.3/libpipewire-module-client-device.so
warning: could not find '.gnu_debugaltlink' file for /usr/lib/x86_64-linux-gnu/pipewire-0.3/libpipewire-module-adapter.so
warning: could not find '.gnu_debugaltlink' file for /usr/lib/x86_64-linux-gnu/pipewire-0.3/libpipewire-module-metadata.so
warning: could not find '.gnu_debugaltlink' file for /usr/lib/x86_64-linux-gnu/pipewire-0.3/libpipewire-module-session-manager.so
[New Thread 0x7ffff58006c0 (LWP 26439)]
[New Thread 0x7ffff4e006c0 (LWP 26440)]
PipeWire : input added [ client: 0, port: 41, device_name: Midi Through, port_name: Midi Through:(capture_0) Midi Through Port-0, display_name: Midi Through Port-0]
PipeWire : output added [ client: 0, port: 40, device_name: Midi Through, port_name: Midi Through:(playback_0) Midi Through Port-0, display_name: Midi Through Port-0]


Displaying ports for: Computer keyboard


Displaying ports for: Dummy


... waiting for hotplug events ...
PipeWire : output added [ client: 0, port: 67, device_name: Arturia KeyLab Essential 61, port_name: Arturia KeyLab Essential 61 2:(playback_0) Arturia KeyLab Essential 61 MID, display_name: Arturia KeyLab Essential 61 MID]
PipeWire : input added [ client: 0, port: 68, device_name: Arturia KeyLab Essential 61, port_name: Arturia KeyLab Essential 61 2:(capture_0) Arturia KeyLab Essential 61 MID, display_name: Arturia KeyLab Essential 61 MID]
PipeWire : output added [ client: 0, port: 69, device_name: Arturia KeyLab Essential 61, port_name: Arturia KeyLab Essential 61 2:(playback_1) Arturia KeyLab Essential 61 DAW, display_name: Arturia KeyLab Essential 61 DAW]
PipeWire : input added [ client: 0, port: 70, device_name: Arturia KeyLab Essential 61, port_name: Arturia KeyLab Essential 61 2:(capture_1) Arturia KeyLab Essential 61 DAW, display_name: Arturia KeyLab Essential 61 DAW]
terminate called after throwing an instance of 'std::logic_error'
  what():  basic_string: construction from null is not valid
ALSA (raw) : input added [ client: 0, container: pci-0000:00:14.0-usb-0:2:1.0, device_id: /sys/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0/sound/card2/controlC2, port: 2, manufacturer: Arturia KeyLab Essential 61, device_name: Arturia KeyLab Essential 61, port_name: Arturia KeyLab Essential 61 MID, display_name: Arturia KeyLab Essential 61 MID, type: hardware, usb]
ALSA (raw) : input added [ client: 0, container: pci-0000:00:14.0-usb-0:2:1.0, device_id: /sys/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0/sound/card2/controlC2, port: 4294967298, manufacturer: Arturia KeyLab Essential 61, device_name: Arturia KeyLab Essential 61, port_name: Arturia KeyLab Essential 61 DAW, display_name: Arturia KeyLab Essential 61 DAW, type: hardware, usb]

Thread 2 "midiobserve" received signal SIGABRT, Aborted.
[Switching to Thread 0x7ffff6c006c0 (LWP 26436)]
__pthread_kill_implementation (no_tid=0, signo=6, threadid=<optimized out>) at ./nptl/pthread_kill.c:44
warning: 44     ./nptl/pthread_kill.c: Aucun fichier ou dossier de ce nom
(gdb) 

Thank you for your help.

[jcelerier]

hello! thanks, that looks like a proper bug. Could you print the backtrace with bt and share it ?

[obook]

(gdb) bt
#0  __pthread_kill_implementation (no_tid=0, signo=6, threadid=<optimized out>) at ./nptl/pthread_kill.c:44
#1  __pthread_kill_internal (signo=6, threadid=<optimized out>) at ./nptl/pthread_kill.c:78
#2  __GI___pthread_kill (threadid=<optimized out>, signo=signo@entry=6) at ./nptl/pthread_kill.c:89
#3  0x00007ffff784527e in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#4  0x00007ffff78288ff in __GI_abort () at ./stdlib/abort.c:79
#5  0x00007ffff7ca5ff5 in __gnu_cxx::__verbose_terminate_handler () at ../../../../src/libstdc++-v3/libsupc++/vterminate.cc:95
#6  0x00007ffff7cbb0da in __cxxabiv1::__terminate (handler=<optimized out>) at ../../../../src/libstdc++-v3/libsupc++/eh_terminate.cc:48
#7  0x00007ffff7ca58e6 in __cxa_call_terminate (ue_header_in=0x7ffff00019f0) at ../../../../src/libstdc++-v3/libsupc++/eh_call.cc:56
#8  0x00007ffff7cba8ba in __cxxabiv1::__gxx_personality_v0 (version=<optimized out>, actions=6, exception_class=5138137972254386944, ue_header=0x7ffff00019f0, context=0x7ffff6bff8a0)
    at ../../../../src/libstdc++-v3/libsupc++/eh_personality.cc:692
#9  0x00007ffff7f40b06 in _Unwind_RaiseException_Phase2 (exc=exc@entry=0x7ffff00019f0, context=context@entry=0x7ffff6bff8a0, frames_p=frames_p@entry=0x7ffff6bff7a8) at ../../../src/libgcc/unwind.inc:64
#10 0x00007ffff7f415cd in _Unwind_Resume (exc=0x7ffff00019f0) at ../../../src/libgcc/unwind.inc:242
#11 0x00005555555a9926 in libremidi::get_udev_soundcard_info (helper=..., card=2) at /home/user/Dev/MIDI/libremidi/include/libremidi/backends/linux/udev.hpp:183
#12 0x00005555555d139d in libremidi::alsa_seq::observer_impl<libremidi::alsa_seq::observer_configuration>::to_port_info<true> (this=0x55555565c9a0, p=...)
    at /home/user/Dev/MIDI/libremidi/include/libremidi/backends/alsa_seq/observer.hpp:160
#13 0x00005555555c8e91 in libremidi::alsa_seq::observer_impl<libremidi::alsa_seq::observer_configuration>::register_port (this=0x55555565c9a0, client=24, port=0)
    at /home/user/Dev/MIDI/libremidi/include/libremidi/backends/alsa_seq/observer.hpp:236
#14 0x00005555555c0f52 in libremidi::alsa_seq::observer_impl<libremidi::alsa_seq::observer_configuration>::handle_event (this=0x55555565c9a0, ev=...)
    at /home/user/Dev/MIDI/libremidi/include/libremidi/backends/alsa_seq/observer.hpp:270
#15 0x00005555555bab70 in libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}::operator()() const (__closure=0x55555569b4e8) at /home/user/Dev/MIDI/libremidi/include/libremidi/backends/alsa_seq/observer.hpp:337
#16 0x00005555555eb174 in std::__invoke_impl<void, libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}>(std::__invoke_other, libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}&&) (__f=...) at /usr/include/c++/13/bits/invoke.h:61
#17 0x00005555555ea984 in std::__invoke<libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}>(libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}&&) (__fn=...) at /usr/include/c++/13/bits/invoke.h:96
#18 0x00005555555ea284 in std::thread::_Invoker<std::tuple<libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}> >::_M_invoke<0ul>(std::_Index_tuple<0ul>) (this=0x55555569b4e8) at /usr/include/c++/13/bits/std_thread.h:292
#19 0x00005555555e9ee4 in std::thread::_Invoker<std::tuple<libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}> >::operator()() (this=0x55555569b4e8) at /usr/include/c++/13/bits/std_thread.h:299
#20 0x00005555555e8e9c in std::thread::_State_impl<std::thread::_Invoker<std::tuple<libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}> > >::_M_run() (this=0x55555569b4e0) at /usr/include/c++/13/bits/std_thread.h:244
#21 0x00007ffff7cecdb4 in std::execute_native_thread_routine (__p=0x55555569b4e0) at ../../../../../src/libstdc++-v3/src/c++11/thread.cc:104
#22 0x00007ffff789caa4 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:447
#23 0x00007ffff7929c3c in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78
(gdb) 

[jcelerier]

could you give me the backtrace you get if you first do:

(gdb) catch throw
(gdb) r
<... here it should stop when an exception is thrown from  libremidi::get_udev_soundcard_info ...>
(gdb) bt

as right now it's pointing to the end of that function, I guess it's a call within it. I'll secure them all anyways. Thanks!

[obook]

(gdb) bt
#0  0x00007ffff7cbb35a in __cxxabiv1::__cxa_throw (obj=0x7ffff0001a10, tinfo=0x7ffff7e6ee40 <typeinfo for std::logic_error>, dest=0x7ffff7cd1f40 <std::logic_error::~logic_error()>)
    at ../../../../src/libstdc++-v3/libsupc++/eh_throw.cc:81
#1  0x00007ffff7ca91c1 in std::__throw_logic_error (__s=0x5555555ed0c8 "basic_string: construction from null is not valid") at ../../../../../src/libstdc++-v3/src/c++11/functexcept.cc:70
#2  0x000055555556631e in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string<std::allocator<char> > (this=0x7ffff6bffa70, __s=0x0, __a=...)
    at /usr/include/c++/13/bits/basic_string.h:646
#3  0x00005555555a91ec in std::__detail::__variant::_Uninitialized<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, false>::_Uninitialized<char const*&> (
    this=0x7ffff6bffa70) at /usr/include/c++/13/variant:249
#4  0x00005555555a9194 in std::__detail::__variant::_Variadic_union<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>::_Variadic_union<char const*&> (
    this=0x7ffff6bffa70) at /usr/include/c++/13/variant:411
#5  0x00005555555a915c in std::__detail::__variant::_Variadic_union<libremidi::uuid, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>::_Variadic_union<1ul, char const*&> (this=0x7ffff6bffa70) at /usr/include/c++/13/variant:417
#6  0x00005555555a9124 in std::__detail::__variant::_Variadic_union<std::monostate, libremidi::uuid, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>::_Variadic_union<2ul, char const*&> (this=0x7ffff6bffa70) at /usr/include/c++/13/variant:417
#7  0x00005555555a90e4 in std::__detail::__variant::_Variant_storage<false, std::monostate, libremidi::uuid, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>::_Variant_storage<2ul, char const*&> (this=0x7ffff6bffa70) at /usr/include/c++/13/variant:486
#8  0x00005555555a8ffb in std::__detail::__variant::_Copy_ctor_base<false, std::monostate, libremidi::uuid, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>::_Variant_storage<2ul, char const*&> (this=0x7ffff6bffa70) at /usr/include/c++/13/variant:584
#9  0x00005555555a9025 in std::__detail::__variant::_Move_ctor_base<false, std::monostate, libremidi::uuid, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>::_Variant_storage<2ul, char const*&> (this=0x7ffff6bffa70) at /usr/include/c++/13/variant:621
#10 0x00005555555a904f in std::__detail::__variant::_Copy_assign_base<false, std::monostate, libremidi::uuid, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>::_Variant_storage<2ul, char const*&> (this=0x7ffff6bffa70) at /usr/include/c++/13/variant:659
#11 0x00005555555a9079 in std::__detail::__variant::_Move_assign_base<false, std::monostate, libremidi::uuid, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>::_Variant_storage<2ul, char const*&> (this=0x7ffff6bffa70) at /usr/include/c++/13/variant:711
#12 0x00005555555a90ac in std::__detail::__variant::_Variant_base<std::monostate, libremidi::uuid, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>::_Variant_base<2ul, char const*&> (this=0x7ffff6bffa70, __i=...) at /usr/include/c++/13/variant:773
#13 0x00005555555a8fc0 in std::variant<std::monostate, libremidi::uuid, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>::variant<2ul, char const*&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, void> (this=0x7ffff6bffa70) at /usr/include/c++/13/variant:1473
#14 0x00005555555a8f7a in std::variant<std::monostate, libremidi::uuid, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned long>::variant<char const*&, void, void, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, void> (this=0x7ffff6bffa70, __t=@0x7ffff6bffa18: 0x0) at /usr/include/c++/13/variant:1444
#15 0x00005555555a97ec in libremidi::get_udev_soundcard_info (helper=..., card=2) at /home/user/Dev/MIDI/libremidi/include/libremidi/backends/linux/udev.hpp:178
#16 0x00005555555d139d in libremidi::alsa_seq::observer_impl<libremidi::alsa_seq::observer_configuration>::to_port_info<true> (this=0x55555565c9a0, p=...)
    at /home/user/Dev/MIDI/libremidi/include/libremidi/backends/alsa_seq/observer.hpp:160
#17 0x00005555555c8e91 in libremidi::alsa_seq::observer_impl<libremidi::alsa_seq::observer_configuration>::register_port (this=0x55555565c9a0, client=24, port=0)
    at /home/user/Dev/MIDI/libremidi/include/libremidi/backends/alsa_seq/observer.hpp:236
#18 0x00005555555c0f52 in libremidi::alsa_seq::observer_impl<libremidi::alsa_seq::observer_configuration>::handle_event (this=0x55555565c9a0, ev=...)
    at /home/user/Dev/MIDI/libremidi/include/libremidi/backends/alsa_seq/observer.hpp:270
--Type <RET> for more, q to quit, c to continue without paging--
#19 0x00005555555bab70 in libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}::operator()() const (__closure=0x55555569b4e8) at /home/user/Dev/MIDI/libremidi/include/libremidi/backends/alsa_seq/observer.hpp:337
#20 0x00005555555eb174 in std::__invoke_impl<void, libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}>(std::__invoke_other, libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}&&) (__f=...) at /usr/include/c++/13/bits/invoke.h:61
#21 0x00005555555ea984 in std::__invoke<libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}>(libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}&&) (__fn=...)
    at /usr/include/c++/13/bits/invoke.h:96
#22 0x00005555555ea284 in std::thread::_Invoker<std::tuple<libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}> >::_M_invoke<0ul>(std::_Index_tuple<0ul>) (this=0x55555569b4e8) at /usr/include/c++/13/bits/std_thread.h:292
#23 0x00005555555e9ee4 in std::thread::_Invoker<std::tuple<libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}> >::operator()() (this=0x55555569b4e8) at /usr/include/c++/13/bits/std_thread.h:299
#24 0x00005555555e8e9c in std::thread::_State_impl<std::thread::_Invoker<std::tuple<libremidi::alsa_seq::observer_threaded<libremidi::alsa_seq::observer_configuration>::observer_threaded(libremidi::observer_configuration&&, libremidi::alsa_seq::observer_configuration&&)::{lambda()#1}> > >::_M_run() (this=0x55555569b4e0) at /usr/include/c++/13/bits/std_thread.h:244
#25 0x00007ffff7cecdb4 in std::execute_native_thread_routine (__p=0x55555569b4e0) at ../../../../../src/libstdc++-v3/src/c++11/thread.cc:104
#26 0x00007ffff789caa4 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:447
#27 0x00007ffff7929c3c in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78
(gdb) 

[jcelerier]

thanks! I think I fixed it in the PR #155 if you could try !

[obook]

No more crash with branch fix/154, thank you very much.

[jcelerier]

super!