title: Can't seem to get class library projects to build after upgrading aspnet 5 from beta4 to beta5
body: <p>after upgrading from aspnet beta4 to beta5 I have a solution with multiple class library projects and a single web app. I'm getting all kinds of errors.
  So I started over creating a new web app project with users/identity/ef. I worked through all the issues upgrading this project to beta5 and it works.
  Then I added a new class library project to that solution and I get the same kinds of errors as with my other more complex solution.</p>
  
  <p>dnvm list:</p>
  
  <pre><code>   Active Version     Runtime Architecture Location                   Alias
     ------ -------     ------- ------------ --------                   -----
     1.0.0-beta4 clr     x64          C:\Users\Joe\.dnx\runtimes
     1.0.0-beta4 clr     x86          C:\Users\Joe\.dnx\runtimes
     1.0.0-beta4 coreclr x64          C:\Users\Joe\.dnx\runtimes
     1.0.0-beta4 coreclr x86          C:\Users\Joe\.dnx\runtimes
     1.0.0-beta5 clr     x64          C:\Users\Joe\.dnx\runtimes
  *    1.0.0-beta5 clr     x86          C:\Users\Joe\.dnx\runtimes default
  </code></pre>
  
  <p>my solution has this global.json:</p>
  
  <pre><code>{
    "projects": [ "src", "test" ],
     "sdk": {
      "version": "1.0.0-beta5"
  }
  </code></pre>
  
  <p>my class library has this project.json</p>
  
  <pre><code> {
    "version": "1.0.0-*",
    "description": "",
    "authors": [ "" ],
    "tags": [ "" ],
    "projectUrl": "",
    "licenseUrl": "",
  
    "dependencies": {
  "Microsoft.Framework.Configuration.Abstractions": "1.0.0-beta5",
  "System.Runtime": "4.0.20-beta-23019"
  
  
    },
  
    "frameworks": {
  "dnx451": { },
  "dnxcore50": {
    "dependencies": {
      "System.Collections": "4.0.10-beta-3019",
      "System.Linq": "4.0.0-beta-23019",
      "System.Threading": "4.0.10-beta-23019",
      "Microsoft.CSharp": "4.0.0-beta-23019"
  
      }
    }
   }
   }
  </code></pre>
  
  <p>I have a single class file in the class library project:</p>
  
  <pre><code>using Microsoft.Framework.Configuration;
  using System;
  
  namespace myapp.Configuration
  {
  public static class ConfigurationExtensions
  {
  
      public static string GetOrDefault(this IConfiguration config, string key, string defaultIfNotFound)
      {
          string result = config.Get(key);
  
          if (string.IsNullOrEmpty(result)) { return defaultIfNotFound; }
  
          return result;
      }
  
      public static int GetOrDefault(this IConfiguration config, string key, int defaultIfNotFound)
      {
          string result = config.Get(key);
  
          if (string.IsNullOrEmpty(result)) { return defaultIfNotFound; }
  
          return Convert.ToInt32(result);
      }
  
      public static bool GetOrDefault(this IConfiguration config, string key, bool defaultIfNotFound)
      {
          string result = config.Get(key);
  
          if (string.IsNullOrEmpty(result)) { return defaultIfNotFound; }
  
          return Convert.ToBoolean(result);
      }
  
      public static Guid GetOrDefault(this IConfiguration config, string key, Guid defaultIfNotFound)
      {
          string result = config.Get(key);
  
          if (string.IsNullOrEmpty(result)) { return defaultIfNotFound; }
          if (result.Length != 36) { return defaultIfNotFound; }
  
          return new Guid(result);
      }
  }
  }
  </code></pre>
  
  <p>when I try to build I get numerous errors like these:</p>
  
  <p>Error   CS0518  Predefined type 'System.Void' is not defined or imported ClassLibrary1.DNX 4.5.1
  Error   CS0518  Predefined type 'System.Object' is not defined or imported  ClassLibrary1.DNX 4.5.1 
  Error   CS0518  Predefined type 'System.String' is not defined or imported  ClassLibrary1.DNX 4.5.1 
  Error   CS0433  The type 'Guid' exists in both 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' and 'System.Runtime, Version=4.0.20.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'</p>
  
  <p>Any ideas how to resolve these errors</p>
  
  <p><strong>UPDATE</strong>
  with this minimal class library by trial and error I found that if I removed the dependency for System.Runtime from the project.json then this simple class library would build.</p>
  
  <p>So to clarify the problem it seems after updating to beta5 from beta4
  now any project that has any one of these specific dependencies (and probably others but these for sure) will not build and will get these errors about primitive types.</p>
  
  <pre><code>"System.Runtime": "4.0.20-beta-23019"
  "System.ComponentModel.Annotations": "4.0.10-beta-23019"
  "System.Xml.XmlDocument": "4.0.0-beta-23019"
  </code></pre>
  
  <p>unfortunately I do need some of these for my code to work</p>
  
  <p>seems like something is funky in the package dependency chain</p>
  
  <p>so far upgrading to beta5 from beta4 has been a total train wreck for me. I'm hoping maybe someone knows how to resolve these issues but if I get no timely response I guess my next step is to try to go back to beta4 and remove beta5</p>
  
  <p>has anyone else had any luck migrating a multi project solution from beta4 to beta5?</p>