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:

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

Solution

You would need to reinstall and compile the passenger module with the newest Ruby 1.9.3 installation.

gem install passenger

passenger-install-apache2-module

and then modify the apache configuration file as in:

The Apache 2 module was successfully installed.                   

Please edit your Apache configuration file, and add these lines:

   LoadModule passenger_module /usr/local/rvm/gems/ruby-1.9.3-p125/gems/passenger-3.0.11/ext/apache2/mod_passenger.so
   PassengerRoot /usr/local/rvm/gems/ruby-1.9.3-p125/gems/passenger-3.0.11
   PassengerRuby /usr/local/rvm/wrappers/ruby-1.9.3-p125/ruby

After you restart Apache, you are ready to deploy any number of Ruby on Rails
applications on Apache, without any further Ruby on Rails-specific
configuration!

and then reload your apache configuration

sudo /etc/init.di/apache2 reload