option('nkcairo', type: 'feature', value: 'enabled', description: 'Enabling twidgets-cairo backend' ) option('nkegl', type: 'feature', value: 'enabled', description: 'Enabling twidgets-egl backend' ) option('test', type: 'feature', value: 'enabled', description: 'Enabling tests' ) option('nklua', type: 'feature', value: 'enabled', description: 'Enabling lua bindings')