I installed core updates on pantheon dev on one of our sites that has the latest version of Mailchimp (7.x-2.10) enabled. Afterward I went to reports/status report and got this error:
Fatal error: Call to undefined function libraries_detect() in /srv/bindings/6be5ee34f8b340ec85456dfa03c1b2ac/code/sites/all/modules/modules/mailchimp/mailchimp.install on line 43
The core update that I installed was this:
Drupal 7.20 release. This contains security fixes and should be applied by all users. For more information see: http://drupal.org/drupal-7.20 Was: 'Merge branch 'master' of git://github.com/pantheon-systems/drops-7'
I flushed caches and still saw the error. I disabled Mailchimp and the error went away. Since I haven't pushed the core updates to test or live yet, I checked reports/status on the live site and get a blank overlay (no error but nothing else, either). Does this seem like a module installation or configuration problem? Other sites with the same versions of software installed don't have this error.