Non web-geeks can stop reading here.
I've been negligent on updating a bunch of stuff for quite awhile here, so some tech debt had crept up. The server was no longer able to auto-update to the latest versions of things like php, mysql, phpmyadmin, and a handful more, due to pulling things over the years from different repositories.
So for months, when I would hit auto-update with yum or through the gui, it would fail on a number of items with unresolvable dependencies. I want to ultimately update the site software here to vbulletin 3.8.9, from the 3.8.7 that it has been on for years. 3.8.9 provides a number of security and bug fixes, but it also has some new requirements, such as newer versions of php.
I just borked up my other site pretty good by not getting it updated before trying the vB update, so i want to make sure all of the backend is happy here before I take on that update. To do so, I had to uninstall php, php-mysql, phpmyadmin, and even mysql temporarily. Then I reinstalled everything from the most current repositories, and it all came up reasonably happily. There are a pile of little things that then need to be tweaked for the site to actually work (re-enable memcache, reset all php.ini values, reinstall/reconfigure php-pear), but I have a checklist and it goes pretty quickly. And now the end of all of that, when I hit "auto-update", it confirms that everything is at the latest, with no unresolvable errors. And - everything is at a level that should support the update to 3.8.9.
I don't have the energy now for more troubleshooting, so that last piece will be pushed off for another weekend or two.