title: VSCode dependency for XDocument
body: <p>I am trying to write a C# console app to read XML and process using XDocument. It seems straightforward, but I cannot get the intellisense to recognize and the compiler to build the code. I am obviously missing a reference, but don't see which.</p>
  
  <p>Program.cs:</p>
  
  <pre><code>using System;
  using System.Xml.XDocument;
  using System.IO;
  
  namespace TestVSCode
  {
      public class Program
      {
          public static void Main(string[] args)
          {
               XDocument _xml = XDocument.Load(File.ReadAllText(@"C:\Temp\Test.xml"));
               Console.Read();
          }
      }
  } 
  </code></pre>
  
  <p>The project.json file:</p>
  
  <pre><code>{
    "version": "1.0.0-*",
    "description": "TestVSCode Console Application",
    "authors": [ "" ],
    "tags": [ "" ],
    "projectUrl": "",
    "licenseUrl": "",
    "tooling": {
     "defaultNamespace": "TestVSCode"
   },
  
   "dependencies": {
   },
  
    "commands": {
      "TestVSCode": "TestVSCode"
    },
  
    "frameworks": {
     "dnx451": { },
     "dnxcore50": {
       "dependencies": {
          "Microsoft.CSharp": "4.0.1-beta-23516",
          "System.Collections": "4.0.11-beta-23516",
          "System.Console": "4.0.0-beta-23516",
          "System.Linq": "4.0.1-beta-23516",
          "System.Threading": "4.0.11-beta-23516",
          "System.Xml.XDocument": "4.0.11-beta-23516",
          "System.IO": "4.0.11-beta-23516",
          "System.IO.FileSystem": "4.0.1-beta-23516"
        }
      }
    }
  }
  </code></pre>
  
  <p>Running dnu restore works fine, but dnu build gives this error:</p>
  
  <p>C:\Temp\TestVSCode\Program.cs(2,14): DNX,Version=v4.5.1 error CS0234: The type or namespace name 'Xml' does not exist in
   the namespace 'System' (are you missing an assembly reference?)
  C:\Temp\TestVSCode\Program.cs(11,12): DNX,Version=v4.5.1 error CS0246: The type or namespace name 'XDocument' could not
  be found (are you missing a using directive or an assembly reference?)
  C:\Temp\TestVSCode\Program.cs(11,29): DNX,Version=v4.5.1 error CS0103: The name 'XDocument' does not exist in the curren
  t context</p>
  
  <p>Please help me understand what mistake I am doing.</p>
  
  <p>Best regards,
  Vemund Haga</p>