> After more digging, what did the problem turn out to be?
>
>
> .... policykit-1. Yup, during my upgrade, I snagged policykit-1 from
> Devuan. It broke things.
>
> I apt-get remove'd policykit-1, and lookit that, my Reboot/Shutdown
> buttons are back. I didn't even have to restart XFCE.
>
>
> ~jaret

[T.J. ] Thank you. That is actually useful information. I've never really been a fan of policykit, aka polkit. The point behind policykit is to have nonprivileged processes communicate with privileged ones. You give polkit exactly the same password as you would to extend sudo privileges, and it in effect does the same thing. I'm not saying they are exactly the same. They aren't. But they ARE used for exactly the same purposes on a day to day basis. Sudo can be fine-grained as well. It does not have to be an all or nothing approach. Why have two different mechanisms installed to do the same job?

Like most efforts on Linux, the idea is a bit daft. I say that with affection. People mean well, but Linux is hardly an organized system. It is a hodge-podge of hacks, thrown together in a blender. Outside of the kernel, there is very little rhyme or reason. Userspace is always a mess. Then they try to consolidate things into systemd, and make an even bigger mess because systemd is not ABI stable, nor is everything properly documented.