conf_path function does not exists.

Error: Call to undefined function conf_path() in
/home/viktor/dorg/drush/includes/bootstrap.inc, line 784

also I've foundL:

/**
 * This is a copy of Drupal's conf_path function, taken from D7 and
 * adjusted slightly to search from the selected Drupal Root.
 *
 * Drush uses this routine to find a usable site based on a URI
 * passed in via a site alias record or the --uri commandline option.
 *
 * Drush uses Drupal itself (specifically, the Drupal conf_path function)
 * to bootstrap the site itself.  If the implementation of conf_path
 * changes, the site should still bootstrap correctly; the only consequence
 * of this routine not working is that drush configuration files
 * (drushrc.php) stored with the site's settimight not be found.
 */
function drush_conf_path($server_uri, $require_settings = TRUE) {

Ways:
* Create proxy conf_path.
* Replace conf_path to drupal_conf_path.