[alexander@localhost csa]$ rails -v
Rails 3.0.9
[alexander@localhost csa]$ ruby -v
ruby 1.8.7 (2011-06-30 patchlevel 352) [i686-linux]
[alexander@localhost csa]$ rake db:migrate
rake aborted!
You have already activated rake 0.9.2.2, but your Gemfile requires rake 0.8.7. Using bundle exec may solve this.

(See full trace by running task with --trace)