(gdb) backtrace
#0  lcb_luv_update_event (iops=<value optimized out>, sock_i=<value optimized out>, event_opaque=0x0, flags=4,
    cb_data=0xe6a680, cb=0x7ffff684d16c <lcb_instance_connect_handler>) at ../io/common.c:300
#1  0x00007ffff684d368 in lcb_instance_connect_handler (sock=0, which=4, arg=0xe6a680) at src/instance.c:1040
#2  0x00007ffff6a7853f in connect_cb (req=<value optimized out>, status=<value optimized out>) at ../io/socket.c:50
#3  0x00000000005df967 in uv__stream_connect (loop=<value optimized out>, w=<value optimized out>,
    events=<value optimized out>) at ../deps/uv/src/unix/stream.c:789
#4  uv__stream_io (loop=<value optimized out>, w=<value optimized out>, events=<value optimized out>)
    at ../deps/uv/src/unix/stream.c:742
#5  0x00000000005d4594 in ev_invoke_pending (loop=0xdde000) at ../deps/uv/src/unix/ev/ev.c:2145
#6  0x00000000005d028d in uv__poll (loop=0xddd960) at ../deps/uv/src/unix/core.c:248
#7  uv__run (loop=0xddd960) at ../deps/uv/src/unix/core.c:257
#8  0x00000000005d0510 in uv_run (loop=0xddd960) at ../deps/uv/src/unix/core.c:265
#9  0x00000000005892c5 in node::Start(int, char**) ()
#10 0x00007ffff6c9fcdd in __libc_start_main (main=0x598f70 <main>, argc=2, ubp_av=0x7fffffffe658,
    init=<value optimized out>, fini=<value optimized out>, rtld_fini=<value optimized out>,
    stack_end=0x7fffffffe648) at libc-start.c:226
#11 0x000000000058136d in _start ()