Xcode 12.2 Beta 1 was released on 17 Sep 2020 and requires macOS 10.15.4+.
It can be downloaded from https://download.developer.apple.com/Developer_Tools/Xcode_12.2_beta/Xcode_12.2_beta.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 18B5052f)
- macOS 11.0 (Build 20A5374f)
- tvOS 14.2 (Build 18K5027e)
- watchOS 7.1 (Build 18R5552f)
The compilers it contains are:
- clang 12.0.0 (Build 1200.0.32.4)
- swift 5.3.1 (Build 1200.0.35)