Today Rails 2.3 was pushed. Upgrading some applications created a couple of issues.
NameError (uninitialized constant ApplicationController)
In previous versions of Rails, the generator would create application.rb for the Application Controller. In 2.3 the file is now properly named application_controller.rb.
NameError (uninitialized constant ActionController::Caching::Sweeper)
This is a bug that is part of the 2.3 release. The fix is was supposedly resolved according to this ticket previous to 2.3 but something is still off.
If you compile Ruby from scratch you may get this error when starting a script/console session:
`require': no such file to load -- readline (LoadError)
To solve this you need to install the readline ruby extension. Here I assume you are using the 1.8.7 Ruby.
sudo yum install ncurses-devel readline-devel cd ~ mkdir src cd src wget ftp://ftp.ruby-lang.org/pub/ruby/1.8/ruby-1.8.7-p72.tar.gz tar zxvf ruby-1.8.7-p72.tar.gz cd ruby-1.8.7-p72.tar.gz/ext/readline ruby extconf.rb make sudo make install