Xcode 9.2 Release was released on 4 Dec 2017 and requires macOS 10.12.6+.
It can be downloaded from https://download.developer.apple.com/Developer_Tools/Xcode_9.2/Xcode_9.2.xip.
Release notes are located at https://developer.apple.com/library/content/releasenotes/DeveloperTools/RN-Xcode/Chapters/Introduction.html#//apple_ref/doc/uid/TP40001051-CH1-SW936.
The SDKs it contains are:
- iOS 15C107
- macOS 17C76
- tvOS 15K104
- watchOS 15S100
The compilers it contains are:
- clang 9.0.0 (Build 900.0.39.2)
- swift 4.0.3 (Build 900.0.74.1)