[TxMt] Can't execute Ruby Shell because of Xcode

[yitzhakbg]

I'm new to htis and saw some previous postings on xcode. I don't know exactly
what xcode is or even why I need it at all. All I want to do is execute Ruby
code using the <command>R command, but I keep getting and xcodebuild error
saying there is no xcode project in my directory. xcodebuild shows up in my
terminal shell. I know I installed Xcode. How do I configure Textmate so that
shelling out to Ruby will execute correctly with Xcode?