IndexOutOfRangeException when C# Method throws Exception

[saatnik]

When returning the result of a C# method in a Lua script and the C# method is throwing an exception, an unexpected IndexOutOfRangeException occurs:

Unhandled exception. System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at Lua.Runtime.Traceback.get_LastPosition()
   at Lua.LuaRuntimeException.get_Message()
   at LuaCSharpBug.Program.Main(String[] args) in C:\LuaCSharpBug\LuaCSharpBug\Program.cs:line 28

I am using LuaCSharp NuGet package version 0.4.2 in .NET 8.0

My minimal example code to demonstrate this is here:

using Lua;

namespace LuaCSharpBug
{
    internal class Program
    {
        static void Main(string[] args)
        {
            var scriptCodeOk = """
                local s = Greeter:Greet("XY")
                return s
                """;
            var scriptCodeIdxOutOfBounds = """
                return Greeter:Greet("XY")
                """;

            var _scriptRuntime = LuaState.Create();
            var greeter = new Greeter();
            _scriptRuntime.Environment["Greeter"] = greeter;
            try {
                //var result = _scriptRuntime.DoStringAsync(scriptCodeOk).Result; // This produces the expected error
                var result = _scriptRuntime.DoStringAsync(scriptCodeIdxOutOfBounds).Result; // This produces an IndexOutOfRangeException instead of the expected error
                Console.WriteLine(result[0]);
            }
            catch (Exception ex)
            {
                Console.WriteLine($"ERROR: {ex.Message}");
            }
        }
    }

    [LuaObject]
    public partial class Greeter
    {
        [LuaMember]
        public string Greet(string lang = "EN")
        {
            string res = lang.ToUpperInvariant() switch
            {
                "EN" => "Hello",
                "DE" => "Hallo",
                _ => throw new ArgumentException($"Invalid language"),
            };
            return res;
        }
    }
}