{ inputs, pkgs, lib, config, ... }:
{
nix.nixPath = [
  "nixpkgs=/etc/nixpkgs:nixpkgs-overlays=/etc/nixpkgs-overlays/overlays.nix"
];
nix.extraOptions = "experimental-features = nix-command flakes";
# Note that this will make the target system download Nixpkgs.
nix.registry.nixpkgs.flake = pkgs.path;
# WARNING: this is a hack to avoid copying Nixpkgs
# a second time into the Nix store.
# It makes only sense when Nixpkgs is already in the Nix store,
# and is registered.
environment.etc."nixpkgs".source = pkgs.path;
environment.etc."nixpkgs-overlays".source =
  pkgs.writeTextDir "overlays.nix" ''
    import ${inputs.self + "/nixpkgs/overlays.nix"} ++
    import ${inputs.julm-nix + "/nixpkgs/overlays.nix"}
  '';
}