Runtime crash on iOS16 when iOS17 framework is mentioned

Hi Everyone,

I'm having a strange crash on App launch with iOS16 when I have a reference to an iOS17 only framework in my code.

Even if I wrap the code in #available, I still get the crash on launch; and the code isn't even called yet... just the existence of it causes the crash.

Pretty strange I thought?

The framework is VisionKit, and the code that causes the crash is

if #available(iOS 17, *) {
    // .imageSubject is iOS17 only - but this causes
    // a crash on launch in iOS16 even with the #available check
    interaction.preferredInteractionTypes = .imageSubject
}

The crash is:

  Referenced from: <91ED5216-D66C-3649-91DA-B31C0B55DDA1> /private/var/containers/Bundle/Application/78FD9C93-5657-4FF5-85E7-A44B60717870/XXXXXX.app/XXXXXX
  Expected in:     <AF01C435-3C37-3C7C-84D9-9B5EA3A59F5C> /System/Library/Frameworks/VisionKit.framework/VisionKit

Any thoughts anyone??

I know the .imageSubject is iOS17 only, but the #available should catch it - no?

Any why does it crash immediatley on launch, when that code is not even called?

Odd!