(gdb) bt full
#0  0x00007ffff3e61700 in futex_abstimed_wait_cancelable (private=128, abstime=0x7fffd06639c0, expected=0, futex_word=0x7ffff7fda000) at ../sysdeps/unix/sysv/linux/futex-internal.h:205
        __ret = -516
        oldtype = 2
        err = <optimized out>
#1  do_futex_wait (sem=sem@entry=0x7ffff7fda000, abstime=abstime@entry=0x7fffd06639c0) at sem_waitcommon.c:111
        err = <optimized out>
#2  0x00007ffff3e617cf in __new_sem_wait_slow (sem=0x7ffff7fda000, abstime=0x7fffd06639c0) at sem_waitcommon.c:181
        _buffer = {__routine = 0x7ffff3e616b0 <__sem_wait_cleanup>, __arg = 0x7ffff7fda000, __canceltype = -134239271, __prev = 0x0}
        err = <optimized out>
        d = 0
#3  0x00007ffff3e61882 in sem_timedwait (sem=<optimized out>, abstime=<optimized out>) at sem_timedwait.c:36
No locals.
#4  0x00007ffff6554c3e in ?? () from /usr/lib/x86_64-linux-gnu/libjack.so.0
No symbol table info available.
#5  0x00007ffff653de9c in ?? () from /usr/lib/x86_64-linux-gnu/libjack.so.0
No symbol table info available.
#6  0x00007ffff653cfcf in ?? () from /usr/lib/x86_64-linux-gnu/libjack.so.0
No symbol table info available.
#7  0x00007ffff653c7e8 in ?? () from /usr/lib/x86_64-linux-gnu/libjack.so.0
No symbol table info available.
#8  0x00007ffff65540d0 in ?? () from /usr/lib/x86_64-linux-gnu/libjack.so.0
No symbol table info available.
#9  0x00007ffff3e59494 in start_thread (arg=0x7fffd0664700) at pthread_create.c:333
        __res = <optimized out>
        pd = 0x7fffd0664700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140736689751808, 8994931328766348114, 0, 140737488340543, 0, 140737354125376, -8994872979587953838, -8994940070287078574}, 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"
#10 0x00007fffef45893f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97
No locals.