title: You must add a reference to assembly 'mscorlib, Version=4.0.0.0 in Mac
body: <p>I'm trying to compile a ASP.NET Core RC2 Project in a Mac with ASP.NET Core RC2 installed. This is my project.json:</p>
  
  <pre><code>    {
    "userSecretsId": "aspnet-TestCoreRC2-6a20d1d3-f55a-4683-a8ca-5f5fbff19ab4",
  
    "dependencies": {
  
      "Microsoft.AspNetCore.Authentication.Cookies": "1.0.0-rc2-final",
      "Microsoft.AspNetCore.Diagnostics": "1.0.0-rc2-final",
      "Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore": "1.0.0-rc2-final",
      "Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.0.0-rc2-final",
      "Microsoft.AspNetCore.Mvc": "1.0.0-rc2-final",
      "Microsoft.AspNetCore.Razor.Tools": {
        "version": "1.0.0-preview1-final",
        "type": "build"
      },
      "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0-rc2-final",
      "Microsoft.AspNetCore.Server.Kestrel": "1.0.0-rc2-final",
      "Microsoft.AspNetCore.StaticFiles": "1.0.0-rc2-final",
      "Microsoft.EntityFrameworkCore.Sqlite": "1.0.0-rc2-final",
      "Microsoft.EntityFrameworkCore.Tools": {
        "version": "1.0.0-preview1-final",
        "type": "build"
      },
      "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0-rc2-final",
      "Microsoft.Extensions.Configuration.Json": "1.0.0-rc2-final",
      "Microsoft.Extensions.Configuration.UserSecrets": "1.0.0-rc2-final",
      "Microsoft.Extensions.Logging": "1.0.0-rc2-final",
      "Microsoft.Extensions.Logging.Console": "1.0.0-rc2-final",
      "Microsoft.Extensions.Logging.Debug": "1.0.0-rc2-final",
      "Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.0.0-rc2-final",
      "Microsoft.VisualStudio.Web.CodeGeneration.Tools": {
        "version": "1.0.0-preview1-final",
        "type": "build"
      },
      "Microsoft.VisualStudio.Web.CodeGenerators.Mvc": {
        "version": "1.0.0-preview1-final",
        "type": "build"
      }
    },
  
    "tools": {
      "Microsoft.AspNetCore.Razor.Tools": {
        "version": "1.0.0-preview1-final",
        "imports": "portable-net45+win8+dnxcore50"
      },
      "Microsoft.AspNetCore.Server.IISIntegration.Tools": {
        "version": "1.0.0-preview1-final",
        "imports": "portable-net45+win8+dnxcore50"
      },
      "Microsoft.EntityFrameworkCore.Tools": {
        "version": "1.0.0-preview1-final",
        "imports": [
          "portable-net45+win8+dnxcore50",
          "portable-net45+win8"
        ]
      },
      "Microsoft.Extensions.SecretManager.Tools": {
        "version": "1.0.0-preview1-final",
        "imports": "portable-net45+win8+dnxcore50"
      },
      "Microsoft.VisualStudio.Web.CodeGeneration.Tools": {
        "version": "1.0.0-preview1-final",
        "imports": [
          "portable-net45+win8+dnxcore50",
          "portable-net45+win8"
        ]
      }
    },
  
    "frameworks": {
      "net451": {
        "dependencies": {
          "System.Runtime": "4.0.20"
        }
      }   
  
    },
  
    "buildOptions": {
      "emitEntryPoint": true,
      "preserveCompilationContext": true
    },
  
    "runtimeOptions": {
      "gcServer": true
    },
  
    "publishOptions": {
      "include": [
        "wwwroot",
        "Views",
        "appsettings.json",
        "web.config"
      ]
    },
  
    "scripts": {
      "prepublish": [ "npm install", "bower install", "gulp clean", "gulp min" ],
      "postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
    },
  
    "tooling": {
      "defaultNamespace": "TestCoreRC2"
    }
  }
  </code></pre>
  
  <p>This is the error:</p>
  
  <blockquote>
    <p>An error occurred during the compilation of a resource required to
    process this request. Please review the following specific error
    details and modify your source code appropriately.</p>
    
    <p>Generated Code</p>
    
    <p>Cannot define a class or member that utilizes 'dynamic' because the
    compiler required type
    'System.Runtime.CompilerServices.DynamicAttribute' cannot be found.
    Are you missing a reference?
        public class _Views_Home_Index_cshtml : Microsoft.AspNetCore.Mvc.Razor.RazorPage Predefined type
    'System.Boolean' is not defined or imported
        public class _Views_Home_Index_cshtml : Microsoft.AspNetCore.Mvc.Razor.RazorPage The type 'Object' is
    defined in an assembly that is not referenced. You must add a
    reference to assembly 'mscorlib, Version=4.0.0.0, Culture=neutral,
    PublicKeyToken=b77a5c561934e089'.</p>
  </blockquote>
  
  <p>Thanks</p>