nix error.txt

  # Enable The i3 Desktop Environment
  services.xserver.displayManager.lightdm.enable = true;
  services.xserver.displayManager.lightdm.autoLogin.enable = true;
  services.xserver.displayManager.lightdm.autoLogin.user = "patrik";
  # services.xserver.displayManager.setupCommands = ''
  #   xrandr --output eDP-1 --auto --output DP-2 --primary --auto --right-of eDP-1 --output HDMI-1 --auto --right-of DP-2
  # '';
  environment.pathsToLink = [ "/libexec" ]; # links /libexec from derivations to /run/current-system/sw 
  services.xserver = {
    desktopManager = {
      default = "none";
      xterm.enable = false;
    };
    windowManager.i3 = {
      enable = true;
      package = pkgs.i3-gaps;
      extraPackages = with pkgs; [
        dmenu #application launcher most people use
        i3status # gives you the default i3 status bar
        i3lock #default i3 screen locker
        # i3blocks #if you are planning on using i3blocks over i3status
     ];
    };
  };






my-computer$ sudo nixos-rebuild switch 
building Nix...
building the system configuration...
error: 
Failed assertions:
- LightDM auto-login requires that services.xserver.desktopManager.default and
services.xserver.windowManager.default are set to valid values. The current
default session: none is not valid.

(use '--show-trace' to show detailed location information)