Availability.h, UIKit.h, etc not found

Question

I\'m having a great problem here.

I recently downloaded Xcode 4.3 from the Mac App Store, because it had the full-screen feature for Lion. And then, my project stopp

Answer 1

I experienced the same problem after I cloned my old computer to new one with the migration assistant.

I solved it simply by deleting content of DerivedData folder (/Users/userName/Library/Developer/Xcode/DerivedData).

I guess clean uninstall or installing new version of xCode does the same.

Answer 2

I solved it just by reinstalling Xcode.

If something similar happens to you, delete Xcode.app (as it's now just an App), and download it again from the Mac App Store.

I guess it didn't install correctly.

Answer 3

Ivan's answer

Check that "Use Standard System Header Directory Searching" (under "Build Settings") is set to Yes.

For me the "Use Standard System Header Directory Searching" was already set to YES, however I ticked it to NO, then back to YES, and did both a Clean and a Clean Build Folder (Product -> Clean and (ALT) Product -> Clean Build Folder) which seemed to have solved the issue for me.

Now I'm not sure what steps in this process had actually fixed it (I had cleaned the build folder prior to this with no avail), but it worked.

Answer 4

May be in Build Settings -> Valid Architecture there are arm64. So just remove the architecture arm64 and problem solved.

Answer 5

To try reinstall your XCode. I lost a lot of time when look for the problem. Then I tried reinstall my XCode because I could not see header files in each frameworks. And that helped me.

Answer 6

I had the same problem too, Xcode 4.3 can't find Foundation.framework, CoreFoundation.framework and like David Da Silva Contín said, I removed the Xcode 4.3 build 4E109 that was installed over Xcode 4.2 and reinstalled it again, and its everything ok now. Thanks David =D