Restore on .NET Core 2.0 project imports .NET Framework 3.5 package targets

[natemcmaster]

Details about Problem

NuGet product used: dotnet
NuGet version: 4.3.0-preview1
dotnet.exe --version: 2.0.0-preview1-005861

Detailed repro steps so we can see the same problem

Run dotnet restore on this:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="SQLitePCLRaw.lib.e_sqlite3.linux" Version="1.1.4" />
  </ItemGroup>

</Project>

SQLitePCLRaw.lib.e_sqlite3.linux contains a file in build/net35/SQLitePCLRaw.lib.e_sqlite3.linux.targets

Expected

obj/*.csproj.nuget.g.targets does not contain an import to the build/net35/ targets file.

Actual

obj/*.csproj.nuget.g.targets contains:

<?xml version="1.0" encoding="utf-8" standalone="no"?>
<Project ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
  </PropertyGroup>
  <ImportGroup Condition=" '$(ExcludeRestorePackageImports)' != 'true' ">
    <Import Project="$(NuGetPackageRoot)sqlitepclraw.lib.e_sqlite3.linux/1.1.4/build/net35/SQLitePCLRaw.lib.e_sqlite3.linux.targets" Condition="Exists('$(NuGetPackageRoot)sqlitepclraw.lib.e_sqlite3.linux/1.1.4/build/net35/SQLitePCLRaw.lib.e_sqlite3.linux.targets')" />
    <!-- .... -->
  </ImportGroup>
</Project>

cc @JunTaoLuo @ericsink @emgarten @kichalla

[natemcmaster]

FYI - this bug does not appear when targeting netcoreapp1.x.

[natemcmaster]

Closing as external to NuGet. It looks like this is caused by Microsoft.NET.Sdk setting PackageTargetFallback to include net461 on .NET Core 2.0. dotnet/sdk#1133

[natemcmaster]

Moved to dotnet/sdk#1166.