error: Unable to resolve build file: XCBCore.BuildFile (missingTargetProductReference(\"3bf83096e50de72a94699e9afc1133ebe3512682230d04680075c283a974e273\")) (in targ
This was the culprit for my experience of the same error:
After setting the correct version of Command Line Tools (i.e., Xcode 10.2.1; see below) on my system, the error went away!