How do I upgrade my existing Nix installation? After updating the nixpkgs-unstable channel, nixpkgs.nix is still 1.11.16 (and nixpkgs.nixUnstable is a 2.0 pre-release).
Would it be safe to run `curl https://nixos.org/nix/install | sh` (safe as in it won't screw with my existing installed packages), and if so, will that get me Nix 2.0? Or do I still have to wait for nixpkgs-unstable to rebuild?
You can upgrade right now with `nix.package = pkgs.nixUnstable;` in your `~/.nixpkgs/config.nix` [1] or on the command-line: `nix-channel --add https://nixos.org/channels/nixos-unstable nixos` followed by `nix-channel --update` if on any system but NixOS or `nixos-rebuild switch` if on NixOS.