Running `zypper dup` for current Tumbleweed, but also for previous rounds
of upgrades, I noticed postfix is issuing fatal errors.

My system has IPv6 disabled, i.e., is running IPv4 only.

(327/422) Installing: postfix-3.5.10-1.2.x86_64 ...[done]
Additional rpm output:
postconf: fatal: parameter inet_interfaces: no local interface found for ::1
Executing upgrade-configuration.
/usr/sbin/postconf: fatal: parameter inet_interfaces: no local interface found
for ::1
Updating /etc/sysconfig/postfix ...
Updating /etc/sysconfig/mail ...