Duplicate 'Content' items error when building asp.net core projects in VS 2017 RC

[Gorthog]

Repro:

1. Create new project ASP.NET Core Web Application.
2. Pick ASP.NET Core Web API 1.0.

3. in csproj, paste the following packages

   
   
   <PackageReference Include="AutoMapper" Version="5.2.0" />
   <PackageReference Include="Microsoft.AspNetCore.Cors" Version="1.1.0" />
   <PackageReference Include="Microsoft.AspNetCore.Diagnostics" Version="1.1.0" />
   <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="1.1.0" />
   <PackageReference Include="Microsoft.AspNetCore.Mvc.Core" Version="1.1.0" />
   <PackageReference Include="Microsoft.EntityFrameworkCore" Version="1.1.0" />
   <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="1.1.0" />
   <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="1.1.0-preview4-final" />
   <PackageReference Include="Microsoft.NET.Sdk.Web" Version="1.0.0-alpha-20161104-2-112" />
   <PackageReference Include="Microsoft.NETCore.App" Version="1.1.0" />
   <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.0" />
   <PackageReference Include="Microsoft.AspNetCore.Server.IISIntegration" Version="1.1.0" />
   <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="1.1.0" />
   <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="1.1.0" />
   <PackageReference Include="Microsoft.Extensions.Configuration.FileExtensions" Version="1.1.0" />
   <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="1.1.0" />
   <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="1.1.0" />
   <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="1.1.0" />
   <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="1.1.0" />
   <PackageReference Include="NLog.Extensions.Logging" Version="1.0.0-rtm-alpha5" />
   <PackageReference Include="Shaman.EPPlus" Version="1.0.1.1" />
   <PackageReference Include="Swashbuckle" Version="6.0.0-beta902" />
   <PackageReference Include="System.Linq.Dynamic.Core" Version="1.0.6.9" />

4. rebuild

expected: 
build succeeds. 

actual:
build fails with:

Severity    Code    Description Project File    Line    Suppression State
Error       Duplicate 'Content' items were included. The .NET SDK includes 'Content' items from your project directory by default. You can either remove these items from your project file, or set the 'EnableDefaultContentItems' property to 'false' if you want to explicitly include them in your project file. The duplicate items were: 'web.config'; 'appsettings.Development.json'; 'appsettings.json'; 'Properties\launchSettings.json'; 'runtimeconfig.template.json'    WebApplication1 C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\Sdks\Microsoft.NET.Sdk\build\Microsoft.NET.Sdk.DefaultItems.targets  188 

[jeffkl]

This should be moved to the https://github.com/dotnet/sdk repo.

This error check was introduced at https://github.com/dotnet/sdk/pull/624. @dsplaisted Are the duplicates being caused by package refs?

[dsplaisted]

Moved to https://github.com/dotnet/sdk/issues/758