How to install new iOS base SDK in Xcode 4.3?
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I'm creating an iOS project and I have reason to suspect that my app runs well on iOS 5.1, but not on iOS 5.0.  However, I want it to run perfectly on iOS 5.0.  The problem is, I can't figure out how to use iOS 5.0 as my base SDK in Xcode. I've found the place where I can change sdks (Target > Build Settings), but the only iOS SDK listed there is 5.1.  How can I install base SDK iOS 5.0 in Xcode?  Thanks