WD cron: Attempting to re-run cron while it is already running.

If you see the following error when running 'drush cron' command:


WD cron: Attempting to re-run cron while it is already running. [warning]
Cron run failed.


then you can try:


drush --yes vset cron_semaphore 0
drush cron


If it doesn't help then fire up:


drush sqlc
DELETE FROM variable WHERE name="cron_semaphore";
DELETE FROM variable WHERE name = "cron_last";
exit
drush cc all
drush cron