Rails doesn't find installed gem on server startup


I have a ruby application that I need to install but I'm new to ruby
on rails and I've run into a problem already...

I've installed Ruby 1.8.7, RubyGems 1.5.3 and Rails 2.3.8. These are
the versions required for the application.

I have also installed all the gems specified in the application's .gem
file using "$ gem install ..."
Required gems : haml jrails rails -v 2.3.8 pg heroku_deploy money
validates_email_format_of mogli facebooker2 simple_uuid delayed_job
ssl_requirement recaptcha hoptoad_notifier

When I launch the server executing "$ ruby script/server" from the
application's directory I get the following message :

So I found the solution…

Missing these required gems:
delayed_job < 2

means that the application requires the delayed_job gem with a version less than 2 : as specified in the environment.rb :

config.gem ‘delayed_job’, :version => “<2”

I just had to install a previous version of the delayed_job gem :

$ gem install delayed_job -v 1.8.5