I'm here because this error is apparently not only for the firebases that require xcode 16+.

I've had to retreat to firebase 12.5 from 12.9 (which 12.9 is supposed to be okay with xcode 15.4 but that had problems too)

using Unity 6000.0.36f1 (but also got this error on 6000.2.2f1)

using xcode 15.4

I create a new project, import the 12.5 firebases (auth, cloud functions, firestore, storage)

and build to iOS and on building in xcode it throws the same Cannot find type 'sending' in scope error.

I'm guessing its something to do with some Swift setting somewhere or other in either the Unity side on postprocess or some random swift setting in xcode after its built from Unity. I just cant seem to find any information about it.

So if you're a Swift-ie (lolz)/someone who can help, we need you!

PS: as a Unity dev for over a decade, lemme be the nth person to say this hodgepodge of xcode, unity, cocoapods, java, firebase package support is so ridiculous..!