nil/modules/system/xdg.nix

{ config, pkgs, user, ... }: {
  home-manager.users."${user.name}" = {
    home.packages = with pkgs; [ xdg-utils xdg-launch ];
    xdg.enable = true;
  };

  environment = {
    sessionVariables = {
      # These are the defaults, and xdg.enable does set them, but due to load
      # order, they're not set before environment.variables are set, which could
      # cause race conditions.
      XDG_CACHE_HOME = "$HOME/.cache";
      XDG_CONFIG_HOME = "$HOME/.config";
      XDG_DATA_HOME = "$HOME/.local/share";
      XDG_BIN_HOME = "$HOME/.local/bin";
    };
    variables = {
      # Conform more programs to XDG conventions. The rest are handled by their
      # respective modules.
      ASPELL_CONF = ''
        per-conf $XDG_CONFIG_HOME/aspell/aspell.conf;
        personal $XDG_CONFIG_HOME/aspell/en_US.pws;
        repl $XDG_CONFIG_HOME/aspell/en.prepl;
      '';
      LESSHISTFILE = "$XDG_CACHE_HOME/lesshst";
      WGETRC = "$XDG_CONFIG_HOME/wgetrc";
    };
  };
}