# Theme modules are a special beast. They're the only modules that are deeply # intertwined with others, and are solely responsible for aesthetics. Disabling # a theme module should never leave a system non-functional. { config, lib, ... }: with lib; with lib.my; let cfg = config.modules.themes; in { assertions = [{ assertion = countAttrs (_: x: x.enable) cfg < 2; message = "Can't have more than one theme enabled at a time"; }]; }