alpine ping on macOS failed

[thehajime]

% UMP_VERBOSE=1  ./rump/bin/rexec ./rumpobj/tests/lkick -v /:/  -- /bin/busybox ping -c5 127.0.0.1
mount 9p fs to /
PING 127.0.0.1 (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: seq=0 ttl=64 time=0.096 ms
ping: sendto
thread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskthread_sched_jb() can be used only for host taskt
(snip)
zsh: bus error  UMP_VERBOSE=1 ./rump/bin/rexec ./rumpobj/tests/lkick -v /:/ -- /bin/busybox

1. why ping command failed with ping: sendto ?
2. why thread_sched_jb() messages printed a lot ? possibly rumpuser_panic is called.

[thehajime]

https://travis-ci.org/github/ukontainer/runu/jobs/663868787#L1268