I just updated my Macbook to Mountain Lion, but now I\'m not able to install some gems, because of the below error about headers. I looked around and it seems to have to do
I was able to get things working by just installing "Command Line Tools 10.8 for Xcode - Late July 2012" (not XCode itself) from:
https://developer.apple.com/downloads/index.action
(Follow the "View all downloads" link from the Mac Dev Center page)
FYI, I did not have XCode installed on Lion, just the "Command Line Tools". Not sure if the new XCode command line tools will play nice with the old XCode.