RuntimeIdentifiers is not recognized by sdk in new-style csproj

[yyjdelete]

Tested with dotnet-dev-1.0.0-preview3-004056, and got the error msg.

***\.nuget\packages\microsoft.net.sdk\1.0.0-alpha-20161104-2\build\Microsoft.NET.RuntimeIdentifierInference.targets(45,5): error : RuntimeIdentifier must be set for .NETFramework executables. Consider RuntimeIdentifier=win7-x86 or RuntimeIdentifier=win7-x64. [***\src\x1\x1.csproj]

The build failed. Please fix the build errors and run again.

Replace the RuntimeIdentifiers to RuntimeIdentifier works, but according to the doc, RuntimeIdentifiers should also be an valid property.

The working old-style project.json

{
  "version": "1.0.0-*",
  "buildOptions": {
    "debugType": "portable",
    "emitEntryPoint": true
  },

  "dependencies": {
    //"Microsoft.Extensions.Logging.Console": "1.0.0"
  },

  "frameworks": {
    "net45": {

    },
    "netcoreapp1.0": {
      "imports": "dnxcore50",

      "dependencies": {
        "Microsoft.NETCore.App": {
          //"type": "platform",
          "version": "1.0.1"
        },
        "System.Text.Encoding.CodePages": "4.0.1"
      }
    }
  },
  "runtimes": {
    "win7-x64": {}
  }
}

upgrade to new-style with dotnet migrate.
The not working new-style .csproj

<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" />
  
  <PropertyGroup>
    <TargetFrameworks>net45;netcoreapp1.0</TargetFrameworks>
    <DebugType>portable</DebugType>
    <AssemblyName>x1</AssemblyName>
    <OutputType>Exe</OutputType>
    <RuntimeIdentifiers>win7-x64</RuntimeIdentifiers>
    <PackageTargetFallback Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">$(PackageTargetFallback);dnxcore50</PackageTargetFallback>
  </PropertyGroup>

  <ItemGroup>
    <Compile Include="**\*.cs" />
    <EmbeddedResource Include="**\*.resx" />
    <EmbeddedResource Include="compiler\resources\**\*" />
  </ItemGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Sdk">
      <Version>1.0.0-alpha-20161104-2</Version>
      <PrivateAssets>All</PrivateAssets>
    </PackageReference>
  </ItemGroup>

  <ItemGroup Condition=" '$(TargetFramework)' == 'net45' ">
    <Reference Include="System" />
    <Reference Include="Microsoft.CSharp" />
  </ItemGroup>

  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">
    <PackageReference Include="Microsoft.NETCore.App">
      <Version>1.0.1</Version>
    </PackageReference>
    <PackageReference Include="System.Text.Encoding.CodePages">
      <Version>4.0.1</Version>
    </PackageReference>
  </ItemGroup>

  <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
    <DefineConstants>$(DefineConstants);RELEASE</DefineConstants>
  </PropertyGroup>
  
  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
</Project>

[dsplaisted]

@piotrpMSFT for the migrate issue, @blackdwarf for the docs.

@nguerrera @eerhardt Should we support multiple runtime identifiers via a RuntimeIdentifiers property in the .NET SDK? If so, how would that interact if there are multiple target frameworks?

[nguerrera]

Adding @emgarten for nuget perspective.

[blackdwarf]

@nguerrera so, for the docs, if there is one of X, we should use singular and if there are multiples of X we should use plural?

[emgarten]

Restore supports both RuntimeIdentifier and RuntimeIdentifiers

how would that interact if there are multiple target frameworks?

For restore the RIDs are applied to all TFMs. Per TFM RIDs are not supported in restore, but it has been considered.

[srivatsn]

Another report - https://developercommunity.visualstudio.com/content/problem/7153/convert-aspnet-core-targeting-net462-cannot-build.html

[nguerrera]

Closing as duplicate of #396, the plan for which will fix this.