runtime: net6.0 preview 4 "Entry point was not found." exception when PublishReadyToRun with old Newtonsoft.Json 9.0.1

Description

Using an older version of Newtonsoft.Json 9.0.1 results in an “Entry point was not found.” exception after a PublishReadyToRun publish. With the latest version 13.0.1 of Newtonsoft.Json it works correctly or when PublishReadyToRun is false.

Configuration

• Which version of .NET is the code running on? 6.0.100-preview.4.21255.9 (I also tried out the daily 6.0.100-preview.6.21301.1 build which resulted in the same exception)
• What OS and version, and what distro if applicable? win
• What is the architecture (x64, x86, ARM, ARM64)? x64
• Do you know whether it is specific to that configuration? no

Regression?

Yes, with net6.0 preview 3 this worked.

Other information

csproj:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <Platform>x64</Platform>
    <RuntimeIdentifier>win-x64</RuntimeIdentifier>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0-windows10.0.19041</TargetFramework>
  </PropertyGroup>

  <PropertyGroup>
    <SelfContained>true</SelfContained>
    <PublishReadyToRun>true</PublishReadyToRun>
    <PublishSingleFile>false</PublishSingleFile>
    <PublishTrimmed>false</PublishTrimmed>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Newtonsoft.Json" Version="9.0.1" />
  </ItemGroup>

</Project>

Program.cs

using System;

namespace EntryPointNotFound
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                Newtonsoft.Json.Linq.JToken token = Newtonsoft.Json.Linq.JToken.Parse("{}");
                var result = token.ToObject<object>();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message + Environment.NewLine + ex.StackTrace);
            }
            Console.Read();
        }
    }
}

Publish with: dotnet publish -c Release

Console output when running the published exe:

Entry point was not found.
   at System.Collections.Generic.IEnumerable`1.GetEnumerator()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) in System.Private.CoreLib.dll:token 0x60065c5+0x5c
   at Newtonsoft.Json.Utilities.ReflectionUtils.GetFields(Type targetType, BindingFlags bindingAttr) in Newtonsoft.Json.dll:token 0x6000431+0x0
   at Newtonsoft.Json.Utilities.ReflectionUtils.GetFieldsAndProperties(Type type, BindingFlags bindingAttr) in Newtonsoft.Json.dll:token 0x6000428+0x0
   at Newtonsoft.Json.Serialization.DefaultContractResolver.GetSerializableMembers(Type objectType) in Newtonsoft.Json.dll:token 0x60004b0+0xa
   at Newtonsoft.Json.Serialization.DefaultContractResolver.CreateProperties(Type type, MemberSerialization memberSerialization) in Newtonsoft.Json.dll:token 0x60004cc+0x0
   at Newtonsoft.Json.Serialization.DefaultContractResolver.CreateObjectContract(Type objectType) in Newtonsoft.Json.dll:token 0x60004b2+0xe
   at Newtonsoft.Json.Serialization.DefaultContractResolver.CreateContract(Type objectType) in Newtonsoft.Json.dll:token 0x60004c7+0xc9
   at Newtonsoft.Json.Serialization.DefaultContractResolver.ResolveContract(Type type) in Newtonsoft.Json.dll:token 0x60004af+0x38
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent) in Newtonsoft.Json.dll:token 0x60005df+0xe
   at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType) in Newtonsoft.Json.dll:token 0x6000152+0x45
   at Newtonsoft.Json.Linq.JToken.ToObject(Type objectType, JsonSerializer jsonSerializer) in Newtonsoft.Json.dll:token 0x600093e+0x11
   at Newtonsoft.Json.Linq.JToken.ToObject(Type objectType) in Newtonsoft.Json.dll:token 0x600093c+0x2c8
   at Newtonsoft.Json.Linq.JToken.ToObject[T]() in Newtonsoft.Json.dll:token 0x600093b+0x0
   at EntryPointNotFound.Program.Main(String[] args) in C:\Users\xxx\source\repos\EntryPointNotFound\EntryPointNotFound\Program.cs:line 11

Reference https://github.com/NuGetPackageExplorer/NuGetPackageExplorer/issues/1284