createrepo_c includes the man page accessible through "man createrepo_c" and
through the traditional name "man createrepo", e.g.

/usr/share/man/man8/createrepo.8.gz
/usr/share/man/man8/createrepo_c.8.gz

The contents of createrepo.8.gz contain an additional '\' escaping the
underscore that breaks this functionality. The contents are:

$ zcat /usr/share/man/man8/createrepo.8.gz
.so man8/createrepo\_c.8

Attempting to access the man page through "man createrepo" results in:

$ man createrepo
man: can't resolve man8/createrepo\_c.8
No manual entry for createrepo
Possibly, man page is not installed, try online at:
https://manpages.opensuse.org/createrepo

Removing the '\' allows it to work normally.

Thanks to Georg Pfuetzenreuter via openSUSE Users <users@lists.opensuse.org>
for the investigation.