Xcode 12.2 Beta 3 was released on 13 Oct 2020 and requires macOS 10.15.4+.
It can be downloaded from https://download.developer.apple.com/Developer_Tools/Xcode_12.2_beta_3/Xcode_12.2_beta_3.xip.
Release notes are located at https://developer.apple.com/documentation/xcode-release-notes/xcode-12_2-beta-release-notes/.
The SDKs it contains are:
- iOS 14.2 (Build 18B5072e)
- macOS 11.0 (Build 20A5395d)
- tvOS 14.2 (Build 18K5047e)
- watchOS 7.1 (Build 18R5572e)
The compilers it contains are:
- clang 12.0.0 (Build 1200.0.32.27)
- swift 5.3.1 (Build 1200.0.41)