Apple、デベロッパー向けに Xcode 12 beta 3 (12A8169g)、iOS 14 beta 3 (18A5332f)、iPadOS 14 beta 3 (18A5332f)、watchOS 7 beta 3 (18R5340d)、tvOS 14 beta 3 (18J5344d) を配布開始
https://developer.apple.com/news/releases/