Simple Crash detection

I am trying to get simple crash detection working. Ten years ago was that no problem with Obj-C thankss to the UncaughtExceptionHandler. But Swift needs more work and I am not sure I am on the right path after I the TheEskimos posts.

I tried the following implementation, based on other approaches and comments. To my surprise it seems not to get called. Any idea what I am missing or doing wrong?

import Foundation

class CrashDetection: NSObject {
    private static let observedSignals = [SIGABRT, SIGILL, SIGSEGV, SIGFPE, SIGBUS, SIGPIPE, SIGTRAP]
    private static var previousSignalHandlers: [Int32:(@convention(c) (Int32) -> Void)] = [:]

    @objc class func start() {
        NSSetUncaughtExceptionHandler(CrashDetection.recieveException)
        observedSignals.forEach { signalType in
            let oldHandler = signal(signalType, CrashDetection.recieveSignal)
            CrashDetection.previousSignalHandlers[signalType] = oldHandler
        }
    }

    private static let recieveException: @convention(c) (NSException) -> Swift.Void = {
        (recieveException) -> Void in
        UserDefaults.standard.setValue(true, forKey: "crashDidOccur")
    }

    private static let recieveSignal: @convention(c) (Int32) -> Void = {
        (recievedSignal) -> Void in
        UserDefaults.standard.setValue(true, forKey: "crashDidOccur")
        NSSetUncaughtExceptionHandler(nil)
        observedSignals.forEach { signalType in
            signal(signalType, previousSignalHandlers[signalType])
        }
    }

}