PropertyInvariant exception is being caught in Core.Aspekt OnException handler

[quentinlautischer]

   class QAspekt : Aspekt.Aspect
    {
        public override void OnException(MethodArguments args, Exception e)
        {
            Console.WriteLine($"Arguments: {args.Arguments.ElementAt(0).Value} Exception: {e.Message}");
        }
    }

    [PropertyInvariant(nameof(DontNullMe), Contract.Constraint.NotNull)]
    class ThrairPrinter
    {
        private string DontNullMe { get; set; } = "Q";

        [QAspekt]
        public void Print(String str)
        {
            DontNullMe = null;
            Console.WriteLine(str);
        }
    }

Console

Hello World
Arguments: Hello World Exception: System.Void AspektTester.ThrairPrinter::set_DontNullMe() post-condition property 'DontNullMe' failed invariant value != null.