Just thought this would be a common error for people using OSX Mavericks

Not sure why the text box is not rendering properly in the github. I'm not entirely sure its needed so, I thought I'd just issue a pull request to make you aware of it (If you already didn't know it..haha! ).
This can be avoided. See: https://github.com/Homebrew/homebrew/blob/master/Library/Formula/gnu-tar.rb#L33