Mac Catalyst error: Cannot override 'paymentQueue' which has been marked unavailable

Question

I have an iOS app in Swift that implements the paymentQueue(_:shouldAddStorePayment:for:) method in SKPaymentTransactionObserver. When I am porting this app to Mac using Mac Catalyst, however, whenever I try to compile and run it on Mac it gives me this compile error which says "Cannot override 'paymentQueue' which has been marked unavailable".

I tried adding #if os(iOS) ... #endif and @available(iOS 11, *) statements around the paymentQueue method but it still gives me this error.

Here is the error-ridden code currently:

#if os(iOS)
func paymentQueue(_ queue: SKPaymentQueue, shouldAddStorePayment payment: SKPayment, for product: SKProduct) -> Bool {
    return true
}
#endif

Anyone else encountering this problem?

Answer 1

You can prevent code from being compiled into a Mac Catalyst build with the !targetEnvironment(macCatalyst) condition:

#if !targetEnvironment(macCatalyst)
func paymentQueue(_ queue: SKPaymentQueue,
                  shouldAddStorePayment payment: SKPayment,
                  for product: SKProduct) -> Bool {
    return true
}
#endif