This is the output after (gdb) t a a bt:

Thread 13 (Thread 0x7fffcdffb700 (LWP 7985)):
#0  0x00007ffff6bc4729 in __GI___poll (fds=0x555555f4b270, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007ffff7426cb6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ffff7426ddc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff7fc5ffd in ?? () from /usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so
#4  0x00007ffff744f98d in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007ffff6ca7182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#6  0x00007ffff6bd0b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 11 (Thread 0x7fffceffd700 (LWP 7983)):
#0  syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1  0x00007ffff7471b9a in g_cond_wait_until () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ffff73f80c1 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff73f8681 in g_async_queue_timeout_pop () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007ffff74503f1 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
--Type <RET> for more, q to quit, c to continue without paging--
#5  0x00007ffff744f98d in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#6  0x00007ffff6ca7182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#7  0x00007ffff6bd0b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7fffcffff700 (LWP 7972)):
#0  0x00007ffff6bc4729 in __GI___poll (fds=0x7fffc8007080, nfds=3, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007fffe08359f1 in ?? () from /lib/x86_64-linux-gnu/libpulse.so.0
#2  0x00007fffe0827260 in pa_mainloop_poll () from /lib/x86_64-linux-gnu/libpulse.so.0
#3  0x00007fffe08278ae in pa_mainloop_iterate () from /lib/x86_64-linux-gnu/libpulse.so.0
#4  0x00007fffe0827960 in pa_mainloop_run () from /lib/x86_64-linux-gnu/libpulse.so.0
#5  0x00007fffe0835939 in ?? () from /lib/x86_64-linux-gnu/libpulse.so.0
#6  0x00007fffe07d5788 in ?? () from /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-12.2.so
#7  0x00007ffff6ca7182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#8  0x00007ffff6bd0b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
--Type <RET> for more, q to quit, c to continue without paging--

Thread 6 (Thread 0x7fffe3fff700 (LWP 7969)):
#0  0x00007ffff6cb1440 in __GI___nanosleep (requested_time=0x7fffe3ffe800, remaining=0x0) at ../sysdeps/unix/sysv/linux/nanosleep.c:28
#1  0x00005555555b5c66 in tr_wait_msec ()
#2  0x00005555555b2772 in ?? ()
#3  0x000055555559f63a in ?? ()
#4  0x00007ffff6ca7182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#5  0x00007ffff6bd0b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7ffff0b4f700 (LWP 7968)):
#0  0x00007ffff6bd0e3f in epoll_wait (epfd=12, events=0x7fffdc000e20, maxevents=32, timeout=39) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30
#1  0x00007ffff71b02c5 in ?? () from /lib/x86_64-linux-gnu/libevent-2.1.so.6
#2  0x00007ffff71a6114 in event_base_loop () from /lib/x86_64-linux-gnu/libevent-2.1.so.6
#3  0x00005555555b4b48 in ?? ()
#4  0x000055555559f63a in ?? ()
#5  0x00007ffff6ca7182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#6  0x00007ffff6bd0b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:--Type <RET> for more, q to quit, c to continue without paging--
95

Thread 4 (Thread 0x7ffff1a3f700 (LWP 7967)):
#0  0x00007ffff6bc4729 in __GI___poll (fds=0x7fffe802bbb0, nfds=8, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007ffff7426cb6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ffff7427042 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff7662c76 in ?? () from /lib/x86_64-linux-gnu/libgio-2.0.so.0
#4  0x00007ffff744f98d in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007ffff6ca7182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#6  0x00007ffff6bd0b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7ffff2a41700 (LWP 7965)):
#0  0x00007ffff6bc4729 in __GI___poll (fds=0x555555659cc0, nfds=2, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007ffff7426cb6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ffff7426ddc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff7426e21 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007ffff744f98d in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
--Type <RET> for more, q to quit, c to continue without paging--
#5  0x00007ffff6ca7182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#6  0x00007ffff6bd0b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7ffff3ae7cc0 (LWP 7960)):
#0  0x00007ffff6bc4729 in __GI___poll (fds=0x555555c71920, nfds=5, timeout=969) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007ffff7426cb6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007ffff7426ddc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007ffff76288bd in g_application_run () from /lib/x86_64-linux-gnu/libgio-2.0.so.0
#4  0x000055555557ac54 in main ()