runtime: Binary Serializing an object with a property of type 'Type' fails with SerializationException

(vs2017 15.3 preview 7.1. dotnet --version: 2.0.1-servicing-006924)

This code:

using System;
using System.Data.SqlClient;
using System.Diagnostics;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;

namespace ConsoleTester
{
    class Program
    {
        static void Main(string[] args)
        {
            BinaryFormatter formatter = new BinaryFormatter();
            MemoryStream stream = new MemoryStream();
            var toSerialize = new Foo() {Bar = "Bar", T = typeof(string)};
            formatter.Serialize(stream, toSerialize);
            stream.Seek(0, SeekOrigin.Begin);
            Foo deserialized = (Foo)formatter.Deserialize(stream);
            stream.Close();

            Console.WriteLine("Deserialized: " + deserialized.Bar);
        }
    }


    [Serializable]
    public class Foo
    {
        public string Bar { get; set; }
        public Type T { get; set; }
    }
}

results in:

Unhandled Exception: System.Runtime.Serialization.SerializationException: Type 'System.RuntimeType' in Assembly 'System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e' is not marked as serializable.
   at System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitSerialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter, SerializationBinder binder)
   at System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Write(WriteObjectInfo objectInfo, NameInfo memberNameInfo, NameInfo typeNameInfo)
   at System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Serialize(Object graph, BinaryFormatterWriter serWriter, Boolean fCheck)
   at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Serialize(Stream serializationStream, Object graph, Boolean check)
   at ConsoleTester.Program.Main(String[] args) in C:\Myprojects\VS.NET Projects\LLBLGen Pro v5.3\UnitTests\LLBLGen Pro\LowLevelAPI\NUnitTests\SelfServicing\ConsoleTester\ConsoleTester\Program.cs:line 16
Press any key to continue . . .

Looking at RuntimeType in CoreCli, it indeed isn’t Serializable, while the type RuntimeType in .NET full is serializable.

This causes problems when porting code over from .NET full to .NET core 2.0 and using BinarySerialization. As the BinaryFormatter is available, one would assume it would work with normal arbitrary code like the simple class above.