[Nix-dev] /etc/nixos/configuration.nix not versioned?

[Wink Saville]

As a newbie I was playing around and last night I rolled back to an
older configuration and realized that the configuration.nix file
didn't rollback. I can now realize that configuration.nix has nothing
to do with booting or running the system and it only builds the
system.

But at the moment I have 20 variations of my system in
/boot/loader/entries/* but only the "latest"
/etc/nixos/configuration.nix. So how are people managing
configuration.nix files and keeping them 'synchronized' with /boot/**/
in particular /boot/loader/entries/* ?

What I've just done is put /etc/nixos into a git repository, but that
puts the burden on me to keep it synchronized with the
/boot/loader/entries. Hopefully there is a better way.

-- Wink