xcode9.1-beta

Swift 4.0 modules were fine in Swift 3.2 apps with Xcode 9.0. But now, with Xcode 9.1, I get: Module compiled with Swift 4.0 cannot be imported in Swift 3.2.1 Or: Module compiled with Swift 4.0 cannot be imported in Swift 4.0.1 Swift 4.0 is compatible with Swift 3.2 only. Swift 4.0.1 is compatible with Swift 3.2.1 only. So: you can't mix 4.0 and 3.2.1 you can't mix 4.0.1 and 3.2 you can't mix 4.0 and 4.0.1 you can't mix 3.2.1 and 3.2 To formulate it differently: you can mix Xcode 9.0 supported Swift versions together you can mix Xcode 9.1 supported Swift versions together you can't mix Xcode 9

Does anyone have any idea to install Xcode 8 OR Xcode 9 without updating macOS? I want to update my Xcode 7.1 to Xcode 8 or Xcode 9 (or 9.1) Beta. But it is not allowing me to update directly on OS X Yosemite 10.10. And I don't want to update my OS to El Capitan now, so how can I install Xcode 8 on OS X Yosemite 10.10. Naup Xcode 8 will work on OS X 10.11 (El Capitan) but the apps you build with won't, because the only SDK available is macOS 10.12 SDK, i.e. macOS Sierra's. From release notes: Compatibility Xcode 8 requires a Mac running macOS Sierra 10.12 or OS X El Capitan 10.11.5 or later.