Drush pm-update strange behavior I have a bunch of sites running both on Drupal 6 and Drupal 7 on my server. Every site has its own folder (ie. I don't use multisites feature). I created a small script to run drush pm-update on every site.

All of this is working okay, but I noticed something strange. Often when I run, either manually or via the script above mentioned, the drush pm-update finds a update for a version of a module or core in one site, but not for others.

I tried to clear drush cache but it showed no result.

Have anyone seen this behavior and has a hint of what it is? I'm curious about it :-)

Update: Now I think it's related to this issue https://drupal.org/node/952394
The thing is, every Drupal site has a variable, in {variable} table, called update_last_check that stores the last time the site had a update check. This variable is mostly update by Drupal cron. It happens that, in some of my sites, this date is too small to need a new check, so Drush skipped it and considered the site up to date. So, in other words, if you want to ensure there's a new update, you should first run a drush cron and then run a drush pm-update.