If you'd like to keep up-to-date with Chrome from unstable but otherwise want to run a stable NixOS release you can do the following:
- Create a file
/etc/nixos/unstable.nix
:
{ config, pkgs, ...}:
let
baseconfig = { allowUnfree = true; };
unstable = import <nixos-unstable> { config = baseconfig; };
in {