Drush can't update : Cannot redeclare system_help

Question

I am trying to use drush to update my drupal core but in some cases (not all) I get

PHP Fatal error: Cannot redeclare system_help() (previously declared in /mysite/modules/system/system.module:46) in /mysite/sites/all/modules/drupal-6.22/modules/system/system.module on line 105 Drush command terminated abnormally due to an unrecoverable error.

Any idea on how to solve this?

Regards.

Answer 1

I had a similar issue, checked and there was inside the core module folder another module folder like: www/module www/module/module

Fixed the issue by reinstalling from scratch that drupal build and also upgraded my version of drush.

Answer 2

I had this same problem and it turns out I (as the system admin) had installed drush globally. The developer had installed it as a system module inside of sites/all/modules.

I removed the sites/all/modules/drush for the site and then was able to drush up as normal.