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

This error tends to be more prevalent in Windows. 

Resolution

Executable permission

Check the permissions of the file to confirm it is executable. If it's not executable, you will need to modify the file in your repository, add executable privilege to the file, then commit and push to the cloud.

Drush missing from composer.json

If drush is missing from composer.json, see the following option to fix this, do all these steps in your local machine:

• Run the following commands

composer config vendor-dir vendor
composer require drush/drush

• If vendor/bin still does not contain a symlink to Drush, you can try regenerating the entire vendor directory again:

rm -rf vendor
composer install

• Alternatively, you can manually create the Drush symlink in vendor/bin as long as vendor/drush/drush/drush has already been installed using Composer:

cd vendor/bin 
ln -s drush ../drush/drush/drush