Reading Greg’s post on security upgrades and a few mentions of patches in the following discussion got me thinking about upgrade methods.

The standard Drupal method is to delete existing files and unpack a tarball to replace the old version - I find this method unappealing because: I keep my code in subversion so don’t want to delete the .svn subdirectories, and sometimes I have patches applied that I don’t want to loose.

The drush script which provides command line access to drupal functionality emits an error message when run as a cron job

tput: No value for $TERM and no -T specified

Drupal has a fairly easy to meet set of requirements http://drupal.org/node/502452

But Drupal projects are free to set their own rules in this area and Drush has used functions only available in PHP 5.2 - as far as I can see this is just the json functions.