Could not find activesupport-3.0.12 in any of the sources (Bundler::GemNotFound)

Problem

You are trying to update your rails app deployed on a server, for example from 3.0.11 to 3.0.12, and at the same time trying to update the Ruby version from 1.9.2 to 1.9.3 but you are getting the following error from passenger:

and then modify the apache configuration file as in:

and then reload your apache configuration