Hi. Recently went through the experience of having to repair my install post OSX update. 2nd time it happened, so this time kept some better notes.
My nix usage: Installed nix (multiuser), and using home-manager as a brew replacement. - so nothing fancy.
First time I upgraded osx, it just replaced the /etc/zshrc, so that was easy to fix. This latest time, the osx upgrade borked the automounting of my Nix Store, so that was a bit more involved to fix. Collected all the info in this gist, which I’ll keep updating every time my install breaks and I learn to fix it.
Please feel free to suggest was to make this better.