Thinking I should wipe the secondary machine (OpenSuse Tumbleweed) and replace it with OpenSuse Leap or even better Devuan. In the ten days since I last ran `sudo zypper dup`, there are thousands of packages to update and it's been like this for some time.

(I've run Gentoo & Funtoo, Arch [briefly ... never again], and NixOS, but none of them had this kind of sustained package churn.)