Make nh work

hosts/default/configuration.nix

@@ -12,6 +12,8 @@
       ../../modules/nixos/nvidia.nix
       # Gnome customization
       ../../modules/nixos/gnome.nix
+      # Nh helper
+      ../../modules/nixos/nh.nix
       # Home-manager
       inputs.home-manager.nixosModules.default
       # Stylix colors
@@ -110,6 +112,10 @@
   # Allow unfree packages
   nixpkgs.config.allowUnfree = true;
 
+  environment.sessionVariables = {
+    FLAKE = "/home/shoi/etc/nixos";
+  };
+
   # List packages installed in system profile. To search, run:
   # $ nix search wget
   environment.systemPackages = with pkgs; [

modules/nixos/nh.nix

@@ -0,0 +1,9 @@
+{ config, pkgs, ... }:
+
+{
+    programs.nh = {
+        enable = true;
+        clean.enable = true;
+        clean.extraArgs = "--keep-since 4d --keep 3";
+    };
+}