UISearchController's init(searchResultsController: UIViewController?) crashes

Question

Calling UISearchController(searchResultsController: nil) in a new ViewController's viewDidLoad() crashes with EXC_BREAKPOINT (code=1, subcode=0x185d73080) (aka, some nil optional was unwrapped).

If I try to execute the code in another new project / playground, it works without crashing.

Having also created a custom UISearchController and having it debugged by breakpoints, it lead me to the init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) method and then it crashed. It might be linked.

I must mention that calling the simple init() does not crash my app.

Exact example:

override func viewDidLoad() {
    super.viewDidLoad()
    UISearchController(searchResultsController: nil)
}

Answer 1

Solved, but it's incredible. I created a new project and added files one by one to see which one interferes with my code.

Seems like I had an extension:

    @IBInspectable var paddingRight: CGFloat {
    get {
        return rightView!.frame.size.width
    }
    set {
        let paddingView = UIView(frame: CGRect(x: 0, y: 0, width: newValue, height: frame.size.height))
        rightView = paddingView
        rightViewMode = .always
    }
}

And that rightView! crashed my app randomly without error.

Lesson learned, extension can provoke that error.