how to use wp-sql prepare statement:

I have this, but am getting the known error:

Missing argument 2 for wpdb::prepare()

(http://make.wordpress.org/core/2012/12/12/php-warning-missing-argument-2-for-wpdb-prepare/)

I see that I need to add second argument, but am not sure what argument or where to add it. Something with ‘%s’ ?

$wpdb->get_results( $wpdb->prepare( $bug_query ), ARRAY_A, $metakey,$metavalue );