.
Thread 4 (Thread 0x7f7f3d780700 (LWP 874)):
#0  0x00007f7f4fd831d1 in __GI_ppoll (fds=0x55eb29dd77f0, nfds=2, timeout=0x7f7f3d77fcd0, sigmask=0x7f7f4fd831d1 <__GI_ppoll+17>) at ../sysdeps/unix/sysv/linux/ppoll.c:35
        tval = {tv_sec = 2, tv_nsec = 49802430}
#1  0x00007f7f514df1a8 in pa_rtpoll_run () from /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecore-10.0.so
No symbol table info available.
#2  0x00007f7f3d782b58 in ?? () from /usr/lib/pulse-10.0/modules/module-null-sink.so
No symbol table info available.
#3  0x00007f7f5127e7d8 in ?? () from /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-10.0.so
No symbol table info available.
#4  0x00007f7f5076a6ca in start_thread (arg=0x7f7f3d780700) at pthread_create.c:456
        __res = <optimized out>
        pd = 0x7f7f3d780700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140184468850432, 428397279812931884, 0, 140722881722927, 140184468851136, 140184468850432, -355920840493215444, -355967013360479956}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
        __PRETTY_FUNCTION__ = "start_thread"
#5  0x00007f7f4fd8f0ff in __GI___sysctl (name=0x100000016, nlen=2, oldval=0x7f7f3d77fcd0, oldlenp=0x0, newval=0x8, newlen=0) at ../sysdeps/unix/sysv/linux/sysctl.c:41
        args = {name = 0xfb0f59e328e4512c, nlen = 0, oldval = 0x0, oldlenp = 0x0, newval = 0x0, newlen = 0, __unused = {0, 0, 0, 140184468850432}}
#6  0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 3 (Thread 0x7f7f4c592700 (LWP 880)):
#0  0x00007f7f4fd831d1 in __GI_ppoll (fds=0x55eb29d57ec0, nfds=3, timeout=0x7f7f4c591c70, sigmask=0x7f7f4fd831d1 <__GI_ppoll+17>) at ../sysdeps/unix/sysv/linux/ppoll.c:35
        tval = {tv_sec = 0, tv_nsec = 64953892}
#1  0x00007f7f514df1a8 in pa_rtpoll_run () from /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecore-10.0.so
No symbol table info available.
#2  0x00007f7f4a80c355 in ?? () from /usr/lib/pulse-10.0/modules/libalsa-util.so
No symbol table info available.
#3  0x00007f7f5127e7d8 in ?? () from /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-10.0.so
No symbol table info available.
#4  0x00007f7f5076a6ca in start_thread (arg=0x7f7f4c592700) at pthread_create.c:456
        __res = <optimized out>
        pd = 0x7f7f4c592700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140184718485248, 428397279812931884, 0, 140722881723055, 140184718485952, 140184718485248, -355958383876091604, -355967013360479956}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
        __PRETTY_FUNCTION__ = "start_thread"
#5  0x00007f7f4fd8f0ff in __GI___sysctl (name=0x100000013, nlen=3, oldval=0x7f7f4c591c70, oldlenp=0x0, newval=0x8, newlen=0) at ../sysdeps/unix/sysv/linux/sysctl.c:41
        args = {name = 0xfb0f59e328e4512c, nlen = 0, oldval = 0x0, oldlenp = 0x0, newval = 0x0, newlen = 0, __unused = {0, 0, 0, 140184718485248}}
#6  0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 2 (Thread 0x7f7f4896b700 (LWP 2002)):
#0  0x00007f7f4fd8310d in fts_children (sp=0xffffffff, instr=702032816) at ../sysdeps/wordsize-64/../../io/fts.c:578
        p = 0x2
        fd = -516
#1  0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 1 (Thread 0x7f7f518a6880 (LWP 1895)):
#0  <signal handler called>
No locals.
#1  0x0000000000000000 in ?? ()
No symbol table info available.
Backtrace stopped: Cannot access memory at address 0x0