nixos-flake/flake.nix

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05";
    #nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
  };
  outputs = { self, nixpkgs, unstable }@attrs: {
    nixosConfigurations.harrowhark = nixpkgs.lib.nixosSystem rec {
      pkgs = import nixpkgs {
        inherit system;
        config = { allowUnfree = true; };
      };
      specialArgs = { inherit unstable; };
      system = "x86_64-linux";
      modules = [
        ./configuration.nix
        # This fixes nixpkgs (for e.g. "nix shell") to match the system nixpkgs
        ({ config, pkgs, options, ... }: {
          nix.registry.nixpkgs.flake = nixpkgs;
        })
      ];
    };
  };
}