Hi, I recently presented a problem to me when building our app Ionic in Xcode6 with the new OS Yosemite. Cordova and CommandLineTools not working. here are the steps to resolve it.
$ git clone git://github.com/phonegap/ios-sim.git
$ cd ios-sim
$ rake install prefix=/usr/local/
If you also have problems with CommandLineTools:
$ sudo xcode-select /Applications//Xcode.app/Contents/Developer/sudo xcode-select /Applications/Xcode6-Beta.app/Contents/Developer
Please comment if you resolved or not resolved it with this post.
My website