LoadError no such file when trying to load gems under rails

I'm getting a 'no such file' error when I try to require some gems in a rails console. Strangely, I don't get this error when requiring them in irb.

Thanks in advance.

        $ irb
irb(main):001:0> $LOAD_PATH
=> ["/usr/local/lib/site_ruby/1.9.1", "/usr/local/lib/site_ruby/1.9.1/x86_64-linux", "/usr/local/lib/site_ruby", "/usr/lib/ruby/vendor_ruby/1.9.1", "/usr/lib/ruby/vendor_ruby/1.9.1/x86_64-linux", "/usr/lib/ruby/vendor_ruby", "/usr/lib/ruby/1.9.1", "/usr/lib/ruby/1.9.1/x86_64-linux"]
        irb(main):002:0> require 'rubygems'
        => true
        irb(main):003:0> require 'image_science'
        => true
        irb(main):004:0> require 'mini_magick'
        => true
        irb(main):005:0> 
        $ rails console
        Loading development environment (Rails 3.0.5)
        irb(main):001:0> require 'rubygems'
        => nil
        irb(main):002:0> require 'image_science'
        LoadError: no such file to load -- image_science
            from /var/lib/gems/1.9.1/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:239:in `require'
    ...
            from script/rails:6:in `require'
            from script/rails:6:in `<main>'
        irb(main):003:0> require 'mini_magick'
        LoadError: no such fil开发者_Python百科e to load -- mini_magick
            from /var/lib/gems/1.9.1/gems/activesupport-3.0.5/lib/active_support/dependencies.rb:239:in `require'
    ...
            from script/rails:6:in `require'
            from script/rails:6:in `<main>'
        irb(main):004:0> $LOAD_PATH
        => ["/var/lib/gems/1.9.1/gems/haml-3.0.25/vendor/fssm/lib",  "/home/username/appname/lib", "/home/username/appname/vendor", "/home/username/appname/app/models", "/home/username/appname/app/mailers", "/home/username/appname/app/helpers", "/home/username/appname/app/controllers", "/var/lib/gems/1.9.1/gems/rails-3.0.5/lib", "/var/lib/gems/1.9.1/gems/railties-3.0.5/lib", "/var/lib/gems/1.9.1/gems/thor-0.14.6/lib", "/var/lib/gems/1.9.1/gems/pg-0.10.1/lib", "/var/lib/gems/1.9.1/gems/pg-0.10.1/ext", "/var/lib/gems/1.9.1/gems/oauth2-0.1.1/lib", "/var/lib/gems/1.9.1/gems/multi_json-0.0.5/lib", "/var/lib/gems/1.9.1/gems/haml-3.0.25/lib", "/var/lib/gems/1.9.1/gems/faraday-0.5.7/lib", "/var/lib/gems/1.9.1/gems/multipart-post-1.1.0/lib", "/var/lib/gems/1.9.1/gems/addressable-2.2.4/lib", "/var/lib/gems/1.9.1/gems/activeresource-3.0.5/lib", "/var/lib/gems/1.9.1/gems/activerecord-3.0.5/lib", "/var/lib/gems/1.9.1/gems/arel-2.0.9/lib", "/var/lib/gems/1.9.1/gems/actionmailer-3.0.5/lib", "/var/lib/gems/1.9.1/gems/mail-2.2.15/lib", "/var/lib/gems/1.9.1/gems/treetop-1.4.9/lib", "/var/lib/gems/1.9.1/gems/polyglot-0.3.1/lib", "/var/lib/gems/1.9.1/gems/mime-types-1.16/lib", "/var/lib/gems/1.9.1/gems/actionpack-3.0.5/lib", "/var/lib/gems/1.9.1/gems/tzinfo-0.3.24/lib", "/var/lib/gems/1.9.1/gems/rack-test-0.5.7/lib", "/var/lib/gems/1.9.1/gems/rack-mount-0.6.13/lib", "/var/lib/gems/1.9.1/gems/rack-1.2.1/lib", "/var/lib/gems/1.9.1/gems/erubis-2.6.6/lib", "/var/lib/gems/1.9.1/gems/activemodel-3.0.5/lib", "/var/lib/gems/1.9.1/gems/i18n-0.5.0/lib", "/var/lib/gems/1.9.1/gems/builder-2.1.2/lib", "/var/lib/gems/1.9.1/gems/activesupport-3.0.5/lib", "/var/lib/gems/1.9.1/gems/abstract-1.0.0/lib", "/var/lib/gems/1.9.1/gems/rake-0.8.7/lib", "/var/lib/gems/1.9.1/gems/bundler-1.0.10/lib", "/usr/local/lib/site_ruby/1.9.1", "/usr/local/lib/site_ruby/1.9.1/x86_64-linux", "/usr/local/lib/site_ruby", "/usr/lib/ruby/vendor_ruby/1.9.1", "/usr/lib/ruby/vendor_ruby/1.9.1/x86_64-linux", "/usr/lib/ruby/vendor_ruby", "/usr/lib/ruby/1.9.1", "/usr/lib/ruby/1.9.1/x86_64-linux", "/var/lib/gems/1.9.1/gems/actionpack-3.0.5/lib/action_controller/vendor/html-scanner", "/var/lib/gems/1.9.1/gems/rack-mount-0.6.13/lib/rack/mount/vendor/multimap", "/var/lib/gems/1.9.1/gems/rack-mount-0.6.13/lib/rack/mount/vendor/regin"]

Gemfile:

source 'http://rubygems.org'

gem 'rails', '3.0.5'

gem 'pg'
gem 'oauth2'
gem 'haml'

You cannot require gems in Rails that are not in your Gemfile. You have to either include them in your Gemfile, or specify the full path to the gem when requiring, e.g. require "/full/path/to/gem".

This is because of the way Bundler works and overrides your existing load path. If you run $LOAD_PATH in the Rails console you'll see that it differs significantly from the one in IRB.