nix-darwin module

The flake-based setup of the Home Manager nix-darwin module is similar to that of NixOS. The flake.nix would be:

{
  description = "Darwin configuration";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
    darwin.url = "github:nix-darwin/nix-darwin";
    darwin.inputs.nixpkgs.follows = "nixpkgs";
    home-manager.url = "github:nix-community/home-manager";
  };

  outputs = inputs@{ nixpkgs, home-manager, darwin, ... }: {
    darwinConfigurations = {
      hostname = darwin.lib.darwinSystem {
        system = "x86_64-darwin";
        modules = [
          ./configuration.nix
          home-manager.darwinModules.home-manager
          {
            home-manager.useGlobalPkgs = true;
            home-manager.useUserPackages = true;
            home-manager.extraSpecialArgs = { inherit inputs; };
            home-manager.users.jdoe = ./home.nix;
          }
        ];
      };
    };
  };
}

Use home-manager.extraSpecialArgs to pass arguments from your flake to home.nix and any imported Home Manager modules. For example, the configuration above makes the complete inputs attrset available to modules, so they can declare arguments such as { inputs, ... }:.

The lower-level mechanism behind this is _module.args. Set _module.args.<name> from inside a module only when you need to provide a module argument from within the module graph itself. For values that originate outside the module graph, such as flake inputs, prefer home-manager.extraSpecialArgs.

Use home-manager.sharedModules for Home Manager modules or settings that should be imported by every user declared in home-manager.users.

The Home Manager configuration is also rebuilt with the nix-darwin generations. The rebuild command here may be darwin-rebuild switch --flake ~/.config/darwin.

You can use the above flake.nix as a template in ~/.config/darwin by

$ nix flake new ~/.config/darwin -t github:nix-community/home-manager#nix-darwin