Re: failed to build nikal error on RHEL7.5 (3.10.0-862.3.2.el7.x86_64)
Yes, RHEL tends to choose a kernel version and sit on it. (RHEL6 is on 2.6.32!!!) Fortunately, openSUSE and other distros tend to stay much more current.
One of the many reasons why I never could take them seriously, and never use their distro for any production system. Also, they always try to make GNU/Linux more and more like Windows, eg. the whole dbus and systemd bs.
BTW: do they meanwhile have any actually usable dist-upgrade mechanism or do they still advice doing a completely fresh install ? 😮 (few years ago, I had to cope w/ a bunch of RHEL instances, and it was so bad, that a fresh install really was the better way) ... something that just works easily on Debian world for over 20 years now.
It really seems, RH is only for people, who really need to waste much $$$ for trivial things.