Comment 4 for bug 1641236

I've reproduced this on a fresh standard xenial instance with LXD
2.0.8 and also on a xenial instance with a patched glibc that reports
ENODEV on ttyname{_r}() on a pty fd that does not exist:

root@x:~# ./enodev_on_pty_in_different_namespace
ttyname(): The pty device might exist in a different namespace: No such device
ttyname_r(): The pty device might exist in a different namespace: No such device