Issue still present on Xcode15 beta 7, and honestly this prevents the creations of connected chains of swiftui packages, to modularize your UI code...

I've opened a TSI, the developer relations confirmed that it should be a bug in SwiftUI, but I've not been told workarounds or hope for a fix

Hi, I've tried your method, but it appears that while exporting localization using that destination (and removing -sdk), it is trying to build also for macOS. If I leave -sdk while adding -destination it starts to compile only for iOS, but the "cannot find external macro" error returns. Maybe the root cause is the same that prevents me to use Xcode itself (not xcodebuild) for exporting localization. While exporting localization from Xcode, if I'm using a package Xcode will try to export the localization both using iOS and macOS sdk (with destination null) Maybe when using the destination flag (instead of the sdk) the localization export tries to compile for both iOS and macOS (Which of course cannot compile due to the fact I'm using iOS only apis)