> The usual quoted workaround for this sysmptom is using setsid(1) so that
> the process is a session leader. However, I don't have any experience with lxc
> to know if that is possible or relevant in this case.

"setsid bash" did not work around this symptom...
On the other hand, logging in by "lxc-attach -n devuan" as root
does not cause this symptom, so it is another workaround...

Best regards, Ryutaroh