ssh login slow, stuck on “pledge: exec” if -v

ssh to a linux box slow after keyed in password, taking 10+ seconds. If using ssh -v, found all the waiting spend on debug info:

debug1: pledge: exec

This usually happen when something stuck on the systemd-logind service.

Restart this service by running

systemctl restart systemd-logind

usually resolves this without rebooting the box.