[New Thread 0x7ffff7fa0700 (LWP 15376)]
.................................autoconnect: system:capture_1 -> send:input_1
.............................autoconnect: system:capture_2 -> send:input_2
....
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff73278f3 in _IO_vfprintf_internal (s=s@entry=0x7fffffffc830, format=<optimized out>, format@entry=0x7ffff7bccdbc "%s", ap=ap@entry=0x7fffffffc998)
    at vfprintf.c:1661
1661	vfprintf.c: No such file or directory.
(gdb) thread apply all bt

Thread 3 (Thread 0x7ffff7fa0700 (LWP 15376)):
#0  0x00007ffff73c83cd in write () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007ffff7bc2c4e in jack_cycle_signal () from /usr/lib/x86_64-linux-gnu/libjack.so.0
#2  0x00007ffff7bc2df0 in jack_process_thread_work () from /usr/lib/x86_64-linux-gnu/libjack.so.0
#3  0x00007ffff6d15182 in start_thread (arg=0x7ffff7fa0700) at pthread_create.c:312
#4  0x00007ffff73d6fbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 2 (Thread 0x7ffff6d0c700 (LWP 15373)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007ffff7bc430b in mb_thread_func () from /usr/lib/x86_64-linux-gnu/libjack.so.0
#2  0x00007ffff6d15182 in start_thread (arg=0x7ffff6d0c700) at pthread_create.c:312
#3  0x00007ffff73d6fbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 1 (Thread 0x7ffff7fdc740 (LWP 15369)):
#0  0x00007ffff73278f3 in _IO_vfprintf_internal (s=s@entry=0x7fffffffc830, format=<optimized out>, format@entry=0x7ffff7bccdbc "%s", ap=ap@entry=0x7fffffffc998)
    at vfprintf.c:1661
#1  0x00007ffff734eff9 in _IO_vsnprintf (string=0x7fffffffca74 "", maxlen=<optimized out>, format=0x7ffff7bccdbc "%s", args=args@entry=0x7fffffffc998) at vsnprintf.c:119
#2  0x00007ffff7330422 in __snprintf (s=<optimized out>, maxlen=<optimized out>, format=<optimized out>) at snprintf.c:33
#3  0x00007ffff7bc3104 in jack_connect () from /usr/lib/x86_64-linux-gnu/libjack.so.0
#4  0x0000000000402da9 in main ()