Apparently this is the proper way to modularize your home config

common/configuration.nix

@@ -2,7 +2,7 @@
 # your system.  Help is available in the configuration.nix(5) man page
 # and in the NixOS manual (accessible by running ‘nixos-help’).
 
-{ config, pkgs, ... }:
+{ inputs, config, pkgs, ... }:
 
 {
   imports = [
@@ -71,6 +71,13 @@
   # Allow unfree packages
   nixpkgs.config.allowUnfree = true;
 
+  home-manager = {
+    extraSpecialArgs = { inherit inputs; };
+    users = {
+      benson = import ../home/home.nix;
+    }
+  };
+
   # Some programs need SUID wrappers, can be configured further or are
   # started in user sessions.
   # programs.mtr.enable = true;

flake.nix

@@ -13,7 +13,7 @@
     emacs-overlay.url = "github:nix-community/emacs-overlay/master";
   };
 
-  outputs = { self, nixpkgs, unstable, home-manager, bashcfg-input, ... }@inputs:
+  outputs = { self, nixpkgs, unstable, home-manager, ... }@inputs:
     let
       system = "x86_64-linux";
       unstable-overlay = final: prev: {
@@ -40,6 +40,7 @@
 
         NixDawn = nixpkgs.lib.nixosSystem {
           inherit system;
+          specialArgs = { inherit inputs };
           modules = [
             home-manager.nixosModule
             { nixpkgs.overlays = [ unstable-overlay ]; }
@@ -49,6 +50,7 @@
 
         NixAdvantage = nixpkgs.lib.nixosSystem {
           inherit system;
+          specialArgs = { inherit inputs };
           modules = [
             home-manager.nixosModule
             { nixpkgs.overlays = [ unstable-overlay ]; }

home/flake.lock

@@ -0,0 +1,48 @@
+{
+  "nodes": {
+    "home-manager": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1704358952,
+        "narHash": "sha256-yazDFmdyKr0JGMqmzQ5bYOW5FWvau8oFvsQ8eSB2f3A=",
+        "owner": "nix-community",
+        "repo": "home-manager",
+        "rev": "c36cb65c4a0ba17ab9262ab3c30920429348746c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "home-manager",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1704194953,
+        "narHash": "sha256-RtDKd8Mynhe5CFnVT8s0/0yqtWFMM9LmCzXv/YKxnq4=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "bd645e8668ec6612439a9ee7e71f7eac4099d4f6",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "home-manager": "home-manager",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

home/flake.nix

@@ -0,0 +1,29 @@
+{
+  description = "Home Manager configuration of benson";
+
+  inputs = {
+    # Specify the source of Home Manager and Nixpkgs.
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    home-manager = {
+      url = "github:nix-community/home-manager";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = { nixpkgs, home-manager, ... }:
+    let
+      system = "x86_64-linux";
+      pkgs = nixpkgs.legacyPackages.${system};
+    in {
+      homeConfigurations."benson" = home-manager.lib.homeManagerConfiguration {
+        inherit pkgs;
+
+        # Specify your home configuration modules here, for example,
+        # the path to your home.nix.
+        modules = [ ./home.nix ];
+
+        # Optionally use extraSpecialArgs
+        # to pass through arguments to home.nix
+      };
+    };
+}

home/home.nix

@@ -0,0 +1,75 @@
+{ config, pkgs, ... }:
+
+{
+  # Home Manager needs a bit of information about you and the paths it should
+  # manage.
+  home.username = "benson";
+  home.homeDirectory = "/home/benson";
+
+  # This value determines the Home Manager release that your configuration is
+  # compatible with. This helps avoid breakage when a new Home Manager release
+  # introduces backwards incompatible changes.
+  #
+  # You should not change this value, even if you update Home Manager. If you do
+  # want to update the value, then make sure to first check the Home Manager
+  # release notes.
+  home.stateVersion = "23.11"; # Please read the comment before changing.
+
+  # The home.packages option allows you to install Nix packages into your
+  # environment.
+  home.packages = [
+    # # Adds the 'hello' command to your environment. It prints a friendly
+    # # "Hello, world!" when run.
+    # pkgs.hello
+
+    # # It is sometimes useful to fine-tune packages, for example, by applying
+    # # overrides. You can do that directly here, just don't forget the
+    # # parentheses. Maybe you want to install Nerd Fonts with a limited number of
+    # # fonts?
+    # (pkgs.nerdfonts.override { fonts = [ "FantasqueSansMono" ]; })
+
+    # # You can also create simple shell scripts directly inside your
+    # # configuration. For example, this adds a command 'my-hello' to your
+    # # environment:
+    # (pkgs.writeShellScriptBin "my-hello" ''
+    #   echo "Hello, ${config.home.username}!"
+    # '')
+  ];
+
+  # Home Manager is pretty good at managing dotfiles. The primary way to manage
+  # plain files is through 'home.file'.
+  home.file = {
+    # # Building this configuration will create a copy of 'dotfiles/screenrc' in
+    # # the Nix store. Activating the configuration will then make '~/.screenrc' a
+    # # symlink to the Nix store copy.
+    # ".screenrc".source = dotfiles/screenrc;
+
+    # # You can also set the file content immediately.
+    # ".gradle/gradle.properties".text = ''
+    #   org.gradle.console=verbose
+    #   org.gradle.daemon.idletimeout=3600000
+    # '';
+  };
+
+  # Home Manager can also manage your environment variables through
+  # 'home.sessionVariables'. If you don't want to manage your shell through Home
+  # Manager then you have to manually source 'hm-session-vars.sh' located at
+  # either
+  #
+  #  ~/.nix-profile/etc/profile.d/hm-session-vars.sh
+  #
+  # or
+  #
+  #  ~/.local/state/nix/profiles/profile/etc/profile.d/hm-session-vars.sh
+  #
+  # or
+  #
+  #  /etc/profiles/per-user/benson/etc/profile.d/hm-session-vars.sh
+  #
+  home.sessionVariables = {
+    # EDITOR = "emacs";
+  };
+
+  # Let Home Manager install and manage itself.
+  programs.home-manager.enable = true;
+}