case "${THIS_SUB_DEPENDS}" in
  WITH_CURL) is_depends_enabled "${SPELL}" curl && ! is_depends_enabled "${SPELL}" libsoup ;;
  WITH_SOUP) is_depends_enabled "${SPELL}" libsoup && ! is_depends_enabled "${SPELL}" curl ;;
          *) message "${PROBLEM_COLOR}bogus sub_depends: $SPELL $THIS_SUB_DEPENDS${DEFAULT_COLOR}" &&
             return 1 ;;
esac
