NSTabView not working in NSAppearanceNamedVibrantDark Popover

Question

When I try to put an NSTabView inside a vibrant dark Popover (as an NSPopover contentViewController's view) I get a completely black background. When I put it in a regular vibrant dark window, it works. When I put it in a vibrant light popover or window it also works.

Here's a screenshot of the result:

As you can see, the controls inside "go through" the black background and show the vibrancy.

Answer 1

Subclass of NSTabView and override allowsVibrancy will fix it:

override var allowsVibrancy: Bool {
    return true
}