In reply to @bzzm3r:matrix.org

I made an attempt to switch from a flakes based NixOS configuration, to a npins managed standard configuration.nix based one. I almost got there, but couldn't figure out the last trick (getting nixos-rebuild to use the pinned packages instead of whatever it has in store). I found various bits of information about it on the internet (in the context of niv, which I think is mostly applicable here, but ultimately couldn't figure out the last little bit (getting nixos-rebuild switch to work), and I am conceptually lost enough now that the most I can do is write out a Discourse post discussing the situation, and hoping for the best.

So, for now, I am tucking my tail between my legs and trotting off back to flakes.nix. The solution might lie in simply doing a live reboot from an iso that is built that is built using an npins managed nixpkgs from the start (rather than rebuild switching into it).

But yeah, I can see why you'd just continue carrying on with flakes.nix, if yours is already quite complicated (mine isn't, it's just a glorified pinned entrypoint into my configuration modules).