We’ve updated Core Data by Tutorials for Xcode 6.1. The update includes a number of small Swift changes and some fixes for errata that readers pointed out. Here’s the official announcement.
If you played with Swift while it was still in beta, you probably realized that your projects would stop compiling going from one Xcode beta to the next.
Even though Swift is technically not in beta anymore, moving from Xcode 6.0 to Xcode 6.1 was no different. We’re still in the (very) early days of Swift.