“Invalid Swift Support - The SwiftSupport folder is missing” with Xcode 7.3.1

Question

After submitting an app update using Application Loader, I got this email from Apple:

We have discovered one or more issues with your recent delivery

Answer 1

The solution here was in this answer. We needed to use the new -exportOptionsPlist flag with xcodebuild instead of the older -exportFormat and -exportWithOriginalSigningIdentity flags. The plist just needs to have the method key set to app-store.