I just did the last XCode update (8.3), and I have the message :
“Swift Language Version” (SWIFT_VERSION) is required to be configured correctly for targets which use Swift. Use the [Edit > Convert > To Current Swift Syntax…] menu to choose a Swift version or use the Build Settings editor to configure the build setting directly.
Knowing that the "Use Legacy Swift Language Version" option has just been removed from the build settings, how can I generate my app in Swift 2.3 without doing any convertion for now ?
You can't. XCode 8.2 was the last version to support Swift 2.3. You have to either update to Swift 3 or use Xcode 8.2.