Xcode 13.2 Archived App Crashes on iOS 14

I'm encountering much of the same problem, and have narrowed my problem down to availability checks within my views, e.g.:

From what I can tell, despite being on an actual device running iOS 14.x, it's trying to run the iOS 15 code - although not a problem on an Intel Mac running it in the simulator.

I have same issue with Xcode 13.2 (13C90), SwiftUI and #available in if statement. Project works fine with old Xcode and in Debug configuration, but crashes with old versions of iOS (iOS 13 & 14) in Release configuration (or using TestFlight).

Steps to reproduce:

1. Create a new SwiftUI iPhone Application project.
2. Set the iOS target to 14
3. Create a simple view with an if #available statement and any new iOS 15 modifier. For example:

struct ContentView: View {

    var body: some View {
		if #available(iOS 15.0, *) {
			List {
				Text("iOS 15 new feature")
					.listRowSeparator(.hidden)
			}
		} else {
			List { Text("Old style") }
		}
    }
}

1. Change the build configuration in the launch scheme to Release and run the app on a device or simulator with iOS 14.

Application will crash with error:

* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x0)
  * frame #0: 0x00007fff2f38f127 libswiftCore.dylib`swift::ResolveAsSymbolicReference::operator()(swift::Demangle::__runtime::SymbolicReferenceKind, swift::Demangle::__runtime::Directness, int, void const*) + 55
    frame #1: 0x00007fff2f3b15dd libswiftCore.dylib`swift::Demangle::__runtime::Demangler::demangleSymbolicReference(unsigned char) + 141
    frame #2: 0x00007fff2f3ae5a8 libswiftCore.dylib`swift::Demangle::__runtime::Demangler::demangleType(__swift::__runtime::llvm::StringRef, std::__1::function<swift::Demangle::__runtime::Node* (swift::Demangle::__runtime::SymbolicReferenceKind, swift::Demangle::__runtime::Directness, int, void const*)>) + 168
    frame #3: 0x00007fff2f394974 libswiftCore.dylib`swift_getTypeByMangledNameImpl(swift::MetadataRequest, __swift::__runtime::llvm::StringRef, void const* const*, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 516
    frame #4: 0x00007fff2f39212d libswiftCore.dylib`swift::swift_getTypeByMangledName(swift::MetadataRequest, __swift::__runtime::llvm::StringRef, void const* const*, std::__1::function<swift::TargetMetadata<swift::InProcess> const* (unsigned int, unsigned int)>, std::__1::function<swift::TargetWitnessTable<swift::InProcess> const* (swift::TargetMetadata<swift::InProcess> const*, unsigned int)>) + 477
    frame #5: 0x00007fff2f39235b libswiftCore.dylib`swift_getTypeByMangledNameInContext + 171
    frame #6: 0x000000010305add7 AvailableBug`__swift_instantiateConcreteTypeFromMangledName at <compiler-generated>:0 
...

It looks like SwiftUI is trying to initialize the content of the if statement and crashes on an unknown modifier or element.

If creates a simple wrapper structure that defers initialization to the "body", everything works fine.

Workaround:

struct LazyContent<Content: View>: View {
	let content: ()->Content

	init (@ViewBuilder content: @escaping ()->Content) {
		self.content = content
	}

	var body: some View {
		content()
	}
}

struct ContentView: View {

    var body: some View {
		if #available(iOS 15.0, *) {
			LazyContent {
				List {
					Text("iOS 15 new feature")
						.listRowSeparator(.hidden)
				}
			}
		} else {
			List { Text("Old style") }
		}
    }
}