Open Radar

 
When using EKEventEditViewController to add or edit an event, the application crashes if the EKEvent used as input to EKEventEditViewController has the startDate field set.

This is true both for creating new events and for editing existing events.

This will only crash on device. On simulator the EventUI is shown as expected but this is output in the console:
2018-10-18 23:01:25.363585+0200 EventKitUICrash[289:5623904] *** -[__NSCFCalendar components:fromDate:]: date cannot be nil
(and a stacktrace similar to when run on device from Xcode

Attached Xcode project that reproduces.

Steps to Reproduce:
1. Create an empty single view iOS project
2. To Info.plist add <key>NSCalendarsUsageDescription</key><string>crash</string>
3. Change ViewController.swift to have this contents:
class ViewController: UIViewController {
    let store = EKEventStore()

    override func viewDidLoad() {
        super.viewDidLoad()

        store.requestAccess(to: .event) { _, _ in
            DispatchQueue.main.async {
                self.showEventEdit()
            }
        }
    }

    func showEventEdit() {
        let event = EKEvent(eventStore: store)
        event.startDate = Date()
        let viewController = EKEventEditViewController()
        viewController.event = event
        viewController.eventStore = store

        present(viewController, animated: true)
    }
}

Expected Results:
EKEventEditViewController to show

Actual Results:
App crashes

Version/Build:
Xcode Version 10.0 (10A255)
iOS 12.0.1