What's the current impl. of NuGet stuff in .csproj? - nuget

Question

I have a few solutions that started out in VS2008 or VS2010 or something like that. They contain some stuff that I think relate to NuGet package restore and including certain MS NuGet packages in the build process.
But this looks different in different projects, while I see no reason for any differences, and a new VS2017 project contains yet another different version.
So, what could I safely do to get my old projects up to date in this regard - what should it look like now, in VS2017?
Both old solutions contain a solution-level subfolder ".nuget" with three files: NuGet.Config, NuGet.exe and NuGet.targets.
The old .csproj files contain these "versions" of NuGet stuff:
Proj1:
<Import Project="$(SolutionDir)\.nuget\nuget.targets" />
<Import Project="..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets" Condition="Exists('..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets')" />
<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
<PropertyGroup>
<ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
</PropertyGroup>
<Error Condition="!Exists('..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets'))" />
</Target>
Proj2 (additional conditions):
<Import Project="$(SolutionDir)\.nuget\NuGet.targets" Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
<Import Project="..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets" Condition="Exists('..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets')" />
<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
<PropertyGroup>
<ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
</PropertyGroup>
<Error Condition="!Exists('$(SolutionDir)\.nuget\NuGet.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\.nuget\NuGet.targets'))" />
<Error Condition="!Exists('..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets'))" />
</Target>
Proj3 (doesn't import nuget.targets):
<Import Project="..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets" Condition="Exists('..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets')" />
<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
<PropertyGroup>
<ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
</PropertyGroup>
<Error Condition="!Exists('..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Bcl.Build.1.0.21\build\Microsoft.Bcl.Build.targets'))" />
</Target>
A new VS2017 web application project (doesn't import nuget.targets or Microsoft.Bcl.Build.1.0.21, different <Error Condition.../> tags):
<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
<PropertyGroup>
<ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
</PropertyGroup>
<Error Condition="!Exists('..\packages\Microsoft.Net.Compilers.2.1.0\build\Microsoft.Net.Compilers.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Net.Compilers.2.1.0\build\Microsoft.Net.Compilers.props'))" />
<Error Condition="!Exists('..\packages\Microsoft.CodeDom.Providers.DotNetCompilerPlatform.1.0.7\build\net45\Microsoft.CodeDom.Providers.DotNetCompilerPlatform.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.CodeDom.Providers.DotNetCompilerPlatform.1.0.7\build\net45\Microsoft.CodeDom.Providers.DotNetCompilerPlatform.props'))" />
</Target>
I would like to have the same setup for all these old projects (unless there would be specific reasons to differ), and I want the setup to be up to date with the tools and environment as per VS2017.
I have automatic package restore enabled and want to keep it that way.
Note: All four projects seem to build and run successfully. Proj2 and Proj3 are unit test projects. Proj1 is really two projects that are identical in this respect.

Answer 1

What's the current impl. of NuGet stuff in .csproj?
To resolve this question, you can follow below steps:
Close Visual Studio to avoid file potential file locks and conflicts.
If using TFS: Remove nuget.exe and nuget.targets from the solution's .nuget folder and remove those files from the solution workspace. Retain nuget.config with the disableSourceControlIntegration setting as explained in Omitting packages with Team Foundation Version Control.
If not using TFS: Remove the .nuget folder from the solution and the solution workspace.
Edit each project file in the solution, remove the <RestorePackages> element, and remove any references to the nuget.targets file.
<RestorePackages>true</RestorePackages>
And
<Import Project="$(SolutionDir)\.nuget\NuGet.targets" Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
<PropertyGroup>
<ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
</PropertyGroup>
<Error Condition="!Exists('$(SolutionDir)\.nuget\NuGet.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\.nuget\NuGet.targets'))" />
</Target>
Note: Retain <Import Project="..\packages\Microsoft.Bcl.Build...
For some details, please refer to:
Nuget: Switching from "Enable Package Restore" to "Automatic Package Restore".