I'm working on a Payment SDK integrating Storekit2 for Unity games. The workflow is as follows: build the swift project that exposes objective c interface to static libraries, then archive them into xcframework embed the xcframework into native unity plugin where we call objective-c functions from C# export the unity project to Xcode project build the game Xcode project When deployment target of swift project is set to iOS15 No matter what iOS version target is set in the game Xcode project, I got build error: Undefined symbol: __swift_FORCE_LOAD_$_swiftCompatibility56 When deployment target of swift project is set to iOS16 And set the deployment target of game project to iOS15 (I need to let the payment sdk to work on iOS15 as Storekit2 and swift concurrency shipped with iOS15). I can build the game Xcode project, and it works on iOS16+ device. But when I run on iOS15 device, I got runtime error: 2024-08-26 18:17:29.289078+0900 ***[1404:95780] Error loading /var/containers/Bundle/Application/123/***/Frameworks/UnityFramework.framework/UnityFramework: dlopen(/var/containers/Bundle/Application/123/***/Frameworks/UnityFramework.framework/UnityFramework, 0x0109): Symbol not found: (_objc_claimAutoreleasedReturnValue) Referenced from: '/private/var/containers/Bundle/Application/123/***/Frameworks/UnityFramework.framework/UnityFramework' Expected in: '/usr/lib/libobjc.A.dylib' 2024-08-26 18:17:29.418604+0900 ***[1404:95780] Error loading /var/containers/Bundle/Application/123/***/Frameworks/UnityFramework.framework/UnityFramework: dlopen(/var/containers/Bundle/Application/123/***/Frameworks/UnityFramework.framework/UnityFramework, 0x0109): Symbol not found: (_objc_claimAutoreleasedReturnValue) Referenced from: '/private/var/containers/Bundle/Application/123/***/Frameworks/UnityFramework.framework/UnityFramework' Expected in: '/usr/lib/libobjc.A.dylib' If I chose not to build framework into static libraries but dynamic ones, I can avoid this problem but Unity cannot handle dynamic libraries well when exporting to Xcode project so I have no choice here but to stick to static ones. minimum reproduction I made a minimum reproduction project to exclude the process of unity. a fresh new empty objective-c app project embed the xcframework built with target iOS15 call a function in the framework in applicationDidFinishLaunch set the deployment target of main target of the app project to iOS15. build the project I still get Undefined symbol: __swift_FORCE_LOAD_$_swiftCompatibility56 versions Xcode version 15.4 Test iOS device version 15.8