Thank you for help. so now I have flake.nix and home.nix in ~/.config/home-manager. flake.nix looks like

`{ description = "Plasma Manager Example";

inputs = { # Specify the source of Home Manager and Nixpkgs home-manager.url = "github:nix-community/home-manager"; nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable"; home-manager.inputs.nixpkgs.follows = "nixpkgs";

plasma-manager. url = "github:pjones/plasma-manager";
plasma-manager. inputs. nixpkgs. follows = "nixpkgs";
plasma-manager. inputs. home-manager. follows = "home-manager";

};

outputs = { home-manager , plasma-manager , nixpkgs , ... }: let system = "x86_64-linux"; username = "naresh"; in { homeConfigurations.${username} = home-manager.lib.homeManagerConfiguration { pkgs = nixpkgs.legacyPackages.${system}; # extraModules = [ # plasma-manager.homeManagerModules.plasma-manager # ];

    modules = [
      # ./home.nix
      # {
      #   home = {
      #     inherit username;
      #     homeDirectory = "/home/${username}";
      #     # Update the state version as needed.
      #     stateVersion = "23.05";
      #   };


      # },
      plasma-manager.homeManagerModules.plasma-manager

    ];


  };
  devShells.${system}.default =
    let pkgs = import nixpkgs { inherit system; }; in
    pkgs.mkShell {
      buildInputs = [
        home-manager.packages.${system}.home-manager
      ];
    };
};

} `

and home.nix looks like

{ config, pkgs, plasma-manager, ... }:

{
  # Home Manager needs a bit of information about you and the paths it should
  # manage.
  home.username = "naresh";
  home.homeDirectory = "/home/naresh";

  # 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 = "23.05"; # Please read the comment before changing.


  imports = [ plasma-manager.homeManagerModules.plasma-manager ];

  # The home.packages option allows you to install Nix packages into your
  # environment.
  home.packages = with pkgs; [
    alacritty
    screenfetch
    konsole
    rnix-lsp
    # # 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}!"
    # '')
  ]; #) ++ ([(builtins.getFlake "github:pjones/plasma-manager")]);

  # 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
    # '';
  };

  # You can also manage environment variables but you will have to manually
  # source
  #
  #  ~/.nix-profile/etc/profile.d/hm-session-vars.sh
  #
  # or
  #
  #  /etc/profiles/per-user/naresh/etc/profile.d/hm-session-vars.sh
  #
  # if you don't want to manage your shell through Home Manager.
  home.sessionVariables = {
    # EDITOR = "emacs";
  };

  # Let Home Manager install and manage itself.
  programs.home-manager.enable = true;

  programs.plasma = {
    enable = true;

    # Some high-level settings:
    workspace.clickItemTo = "select";

    hotkeys.commands."Launch Konsole" = {
      key = "Meta+Alt+K";
      command = "konsole";
    };

    # Some mid-level settings:
    shortcuts = {
      ksmserver = {
        "Lock Session" = [ "Screensaver" "Meta+Ctrl+Alt+L" ];
      };

      kwin = {
        "Expose" = "Meta+,";
        "Switch Window Down" = "Meta+J";
        "Switch Window Left" = "Meta+H";
        "Switch Window Right" = "Meta+L";
        "Switch Window Up" = "Meta+K";
      };
    };

    # A low-level setting:
    configFile."baloofilerc"."Basic Settings"."Indexing-Enabled" = false;
  };
}

and when I run home-manager switch --flake ~/.config/home-manager/ It gives me

`error: … while evaluating a branch condition

     at /nix/store/1ryprai4bllkrna60cmcygxc4qyn79s1-source/lib/lists.nix:57:9:

       56|       fold' = n:
       57|         if n == len
         |         ^
       58|         then nul

   … while calling the 'length' builtin

     at /nix/store/1ryprai4bllkrna60cmcygxc4qyn79s1-source/lib/lists.nix:55:13:

       54|     let
       55|       len = length list;
         |             ^
       56|       fold' = n:

   (stack trace truncated; use '--show-trace' to show the full trace)

   error: The option `home.stateVersion' is used but not defined.

`

Now don't know what to do. I got your latter advice regarding diff but first I need to make this work. I am on unstable nixos version. and

home-manager --version gives 23.11-pre

nixos-version gives 23.11pre546599.e44462d6021b (Tapir)

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