Errno 13: Permission Denied

Issue

If you encounter Errno 13: Permission Denied, this typically indicates a missing executable permission on the file or script. 

For Example:

$ drush @mysitegroup.dev

status Warning: pcntl_exec(): Error has occurred: (errno 13) Permission denied in /usr/local/drush8/vendor/drush/drush/includes/startup.inc on line 422 
Error has occurred executing the Drush script found at /mnt/www/html/mysitegroupdev/vendor/bin/drush 
(errno 13) Permission denied

Resolution

You will need to modify the file in your repository, add executable privilege to it, then commit and push to the cloud.