JSIL LINQ error

tryjsil.cs

using System;
using JSIL;
using JSIL.Meta;
using System.Collections.Generic;
using System.Linq;

public static class Program {
  
  public static void Main () {
    Dictionary<string, string[]> data = new Dictionary<string, string[]>(){
      { "a", new []{"b"}},
      { "b", new string[0]}
	};
      
      var xs = data.Keys.Select(k => new X{ Name = k}).ToList();
    
    xs.ForEach(x => x.Refs = data[x.Name].Select(y => xs.Single(z => z.Name == y)).ToArray());
    
    
    Console.WriteLine("Hello JSIL World!");
 
  }
  
  
  
  public class X 
  {
	public string Name {get;set;}
    public X[] Refs {get;set;}
  }
}