Xcode 11.2.1 GM Seed 1 was released on 5 Nov 2019 and requires macOS 10.14.4+.
It can be downloaded from https://download.developer.apple.com/Developer_Tools/Xcode_11.2.1_GM_Seed/Xcode_11.2.1_GM_Seed.xip.
Release notes are located at https://developer.apple.com/documentation/xcode_release_notes/xcode_11_2_1_gm_seed_release_notes/.
The SDKs it contains are:
- iOS 13.2.2 (Build 17B102)
- macOS 10.15.1 (Build 19B89)
- tvOS 13.2 (Build 17K90)
- watchOS 6.1 (Build 17S80)
The compilers it contains are:
- clang 11.0.0 (Build 1100.0.33.12)
- swift 5.1.2 (Build 1100.0.278)