OK, it drives me crazy! I try to run ruby / rails.
MacBook-Pro-2:Library me$ rvm list rvm rubies ruby-1.9.3-p194 [ x86_64 ] ruby-2.1.0
I would recommend uninstalling ruby-2.1.0 and then reinstalling it as it seems like your current installation is corrupted.
rvm uninstall 2.1.0 rvm install 2.1.0