Debugging aspnet core source code

I would like to debug Security modules of aspnet core rc2. 

I have cloned a respective repository and added a path to projects into my global.json file. When I build my solution I get multiple errors, e.g. 

CS0006: Metadata file 'D:\Projects\aspnet\security\src\Microsoft.AspNetCore.Authorization\bin\Debug\net451\Microsoft.AspNetCore.Authorization.dll' could not be found DataScout.WebApi C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v14.0\DotNet\Microsoft.DotNet.Common.Targets 241

Error CS1061 'IServiceCollection' does not contain a definition for 'AddAuthentication' and no extension method 'AddAuthentication' accepting a first argument of type 'IServiceCollection' could be found (are you missing a using directive or an assembly reference?) DataScout.WebApi..NET Framework 4.6 <path to project>\Startup.cs 42 Active.

project.json:

{"version": "1.0.0-*","buildOptions": {"emitEntryPoint": true,"preserveCompilationContext": true,"compile": {"exclude": [ "wwwroot", "node_modules" ]
    }
  },"publishOptions": {"exclude": [ "**.user", "**.vspscc" ],"include": ["wwwroot","appsettings_production.json","web.config"
    ]
  },"dependencies": {"Microsoft.AspNetCore.Mvc": "1.0.0-rc2-final","Microsoft.AspNetCore.Server.Kestrel": "1.0.0-rc2-final","Microsoft.AspNetCore.Server.IISIntegration": "1.0.0-rc2-final","Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0-rc2-final","Microsoft.Extensions.Configuration.FileExtensions": "1.0.0-rc2-final","Microsoft.Extensions.Configuration.Json": "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.AspNetCore.Diagnostics": "1.0.0-rc2-final","Microsoft.AspNetCore.StaticFiles": "1.0.0-rc2-final","Microsoft.Extensions.Caching.Abstractions": "1.0.0-rc2-final","Microsoft.Extensions.Caching.Memory": "1.0.0-rc2-final","Microsoft.AspNetCore.Authentication.Cookies": "1.0.0-rc2-final","Microsoft.AspNetCore.Authentication.OpenIdConnect": "1.0.0-rc2-final","EntityFramework": "6.1.3","Softius_OpenXmlDll": "1.0.0.1","EntityFramework.Extended": "6.1.0.168","AutoMapper": "4.2.1","Seterlund.CodeGuard": "2.3.4"
  },"tools": {"Microsoft.AspNetCore.Server.IISIntegration.Tools": {"version": "1.0.0-preview1-final","imports": "portable-net45+win8+dnxcore50"
    }
  },"scripts": {"postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
  },"frameworks": {"net46": {"frameworkAssemblies": {
      }
    }
  },"runtimeOptions": {"gcConcurrent": false,"gcServer": true
  }
}