Xcode 12 beta 4 | UINavigationController `setViewControllers` no longer replaces view controllers

Hi,

In the latest beta (Xcode 12 beta 4) we started noticing that calling setViewControllers on UINavigationController no longer replaces the navigation stack, but instead pushes the replacement view controllers.

e.g.

Code Block swift
let navigationController = UINavigationController(rootViewController: originalViewController)
navigationController.setViewControllers([replacementViewController], animated: true)

In Xcode 12 beta 4 it appears the final result (e.g. inspecting navigationController.viewControllers) yields:

[originalViewController, replacementViewController] in the navigation stack

The expectation is the final result would be:

[replacementViewController] in the navigation stack


Note:

• This appears to only occur when animated, when using animated: false the behavior works as expected (view controllers get replaced)

Anyone else witnessing this too? Is there anything obvious we're missing? I've filed a feedback for this FB8280522.

Thanks!