It seems that the systemd/systemctl is removing the /run/courier/authdaemon/pid file underneath courier.
Removing the line "PIDFile=/run/courier/authdaemon/pid" from the installed .service file resolves this problem and upgrade works fine. Amos
- Bug#889961: courier-authdaemon: Upgrade failures in 0.68.0-4... Amos Jeffries
- Bug#889961: courier-authdaemon: Upgrade failures in 0.6... Amos Jeffries
