Nuget Restore ignore references projects - visual-studio-2017

Question

I'm trying to migrate a .NET core library project from VS2015 to VS2017, which will cause the project.json file to be converted into a .csproj file.
Now, the project is referencing two libraries that I've created, and when build are being pushed to VSTS package manager.
When working with the project in Visual Studio I prefer to have the to referenced projects added to my solution, so I can work on the code in the same solution. At the same time I'd like the project to reference the packages, so when build on VSTS it'll pickup the packages instead.
With the project.json file, this worked fine, nuget restore (I'm using nuget restore, since dotnet restore cannot autheticate to VSTS packagemanager) would just restore the packages and I could build it.
Now with the .csproj file, the references projects are added like this:
<ItemGroup">
<ProjectReference Include="myliba\src\myliba.csproj" />
<ProjectReference Include="mylibb\src\mylibb.csproj" />
</ItemGroup>
which will make 'nuget restore' try to restore packages for these projects as well.. but since these projects are in another repository, they are not (and should not) being downloaded from the repository, and 'nuget restore' fails with the error:
Errors in C:\a\1\s\src\mylib\mylib.csproj
Unable to resolve 'C:\a\1\myliba\src\myliba' for '.NETCoreApp,Version=v1.1'.
Unable to resolve 'C:\a\1\mylibb\src\mylibb.csproj' for '.NETCoreApp,Version=v1.1'.
How do I make nuget ignore these ProjectReferences, and make it get the libraries from the VSTS package manager instead?
One solution:
If I define a variable on VSTS called 'BuildSystem' and set it to VSTS, then I can check for this in my .csproj
<ItemGroup Condition=" '$(BuildSystem))' == '' ">
<ProjectReference Include="myliba\src\myliba.csproj" />
<ProjectReference Include="mylibb\src\mylibb.csproj" />
</ItemGroup>
Though it means that I have to tailor all my .csproj manually, which is not optimal

Answer 1

You are using project reference (ProjectReference) instead of package reference. You need to install the corresponding packages from VSTS package feed.
The sample project file code (project and package references):
<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup Label="Globals">
<SccProjectName>SAK</SccProjectName>
<SccProvider>SAK</SccProvider>
<SccAuxPath>SAK</SccAuxPath>
<SccLocalPath>SAK</SccLocalPath>
</PropertyGroup>
<PropertyGroup>
<TargetFramework>netcoreapp1.1</TargetFramework>
</PropertyGroup>
<PropertyGroup>
<PackageTargetFallback>$(PackageTargetFallback);portable-net45+win8+wp8+wpa81;</PackageTargetFallback>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="ClassLibraryCore2017" Version="1.0.0" /><!--package reference-->
<PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.0.0" />
<PackageReference Include="Microsoft.AspNetCore" Version="1.1.1" />
<PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="1.1.1" />
<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="1.1.1" />
<PackageReference Include="Microsoft.VisualStudio.Web.BrowserLink" Version="1.1.0" />
</ItemGroup>
<ItemGroup>
<DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="1.0.0" />
</ItemGroup>
<ItemGroup>
<ProjectReference Include="..\ClassLibrary1\ClassLibrary1.csproj" /><!--project reference-->
</ItemGroup>
</Project>
You can refer to these steps to achieve your requirement:
Add VSTS feed to Nuget source by calling
this command
nuget sources add -name [feed name] -source [your vsts feed] -username test -password [personal access token] -StorePasswordInClearText
Install packages from your VSTS feed to your project via VS 2017.
Add Nuget.config (in %appdata%\Nuget folder) to the source control (at the same level of solution file)
Check in changes
If you are using NuGet Installer step/task, specify NuGet.config in Path to NuGet.Config input box.
If you are using .Net Core (Preview) step/task, specify this arguments in Arguments input box: --configfile ..\Config\NuGet.Config