I also encountered a similar infinite loop on a swizzling method which replaces viewDidAppear to augment additional logging stuff, and it works well until I built the project with Xcode 12 beta 6 on an iOS14 simulator(iPhone 11 pro max). My project is built with swift UI for demo. Looks like it only causes problems on a project with SwiftUI on iOS14 Say that we have 1. an ContentView for our swiftUI project 2. an abc_viewDidAppear swizzled function for viewDidAppear which calls abc_viewDidAppear(should be the original viewDidAppear impl after swizzling) inside itself (void)abc_viewDidAppear:(BOOL)animated { 	if (meet some conditions) { 		/* do some logging stuff	*/     [self abc_viewDidAppear:animated]; 		/* do some logging stuff */   } else { 		/* do nothing but call the original viewDidAppear which was swizzled */     [self abc_viewDidAppear:animated];   } } When I tracked when my abc_viewDidAppear gets called: Before iOS14 called by ContentView(actually something like 1234SwiftUI00UIHostingControllerV11Demo22ContentView) -> call the original viewDidAppear iOS14 called by ContentView -> call the original viewDidAppear called by an internal swift ui component - ViewList.View?(also a UIViewController) 1234SwiftUI00UIHostingControllerVS14ViewListView_ => this causes an infinite loop by calling abc_viewDidAppear -> abc_viewDidAppear is mine instead of the original viewDidAppear after swizzling

Looks good on xcode 13.2