Unsupported compiler 'com.apple.compilers.llvm.clang.1_0' selected for architecture 'x86_64' on Xcode 7 Beta 2

Question

When I incorporated a popular OAuth2 library in iOS called OAuth2Client to my iOS app which is developed on Xcode 7 Beta 2 and then tried running the simulator, the following error occurred and the simulator didn't launch.

Unsupported compiler 'com.apple.compilers.llvm.clang.1_0' selected for architecture 'x86_64'

What does this error mean? A lot of warnings (yellow triangle) followed with the error above (red octagon), such as:

warning: no rule to process file '/Users/myUsername/myAppname/Pods/NXOAuth2Client/Sources/NSData+NXOAuth2.m' of type sourcecode.c.objc for architecture x86_64

How can I deal with the these errors and run the simulator properly? Or does CocoaPods only work on environments prior to Xcode 7 Beta?

UPDATE

Later I found that this occurs on any projects I create, not only on a project using CocoaPods. The only clue that occurs to me is that when I updated my iTunes to 12.2 today and then launched my Xcode, the dialog popped up, instructing to install new command-line tools.

UPDATE 2

I just upgrade to Xcode 7 Beta 3 but the error still got me annoyed...

Answer 1

I met the same issue on Xcode 7 beta 4. I have tried to clean the project for several times but with no lucky. Unbelievably, restart Xcode saved my night. You can try this.

Answer 2

Solution 1

Close Xcode, open terminal, before anything else, type: “defaults delete com.apple.dt.Xcode” (this addresses your Xcode settings) open Xcode and your project should work normally.

Plan B

If that doesn't work try this to clear out your cache. Save your files then put this in your terminal:
rm -rf Library/Caches/com.apple.dt.Xcode/

Potential causes

This bug can occur if you declared your pods with single quotes instead of double quotes or for some reason your pod files become corrupted (i.e.: working with p.lists, Google's p.list, firebase etc). I think what triggers the bug to break your code is during certain recompiling phases, for example: opening after unzipping the project, or opening the project after pulling it from GitHub.

Answer 3

With the version (X-code 8 beta 2) I got the following error, because I tried to run it out of the downloads folder:

Unsupported compiler 'com.apple.compilers.llvm.clang.1_0' selected for architecture 'x86_64'

It helped to put it in the normal Program Folder!