Uploaded from TextMate

From ZSH 

macgem install aws-s3                                                                                                                                             
Successfully installed aws-s3-0.6.2
1 gem installed

macirb                                                                                                                                                            
irb(main):001:0> require 'json'
=> true
irb(main):002:0> require 'aws/s3'
=> true

but

From XCode

/Users/orta/Library/Developer/Xcode/DerivedData/photouploader-eobdmmzdybkzshcqiesyuxuupiik/Build/Products/Debug/photouploader.app/Contents/Resources/rb_main.rb:16:in `<main>': no such file to load -- aws/s3 (LoadError)