Restore failures with mixed projects (PC & PR) & global packages folder and packages folder point to the same location

[bitbonk]

I have a solution that contains both project with the new (.NET Core) csproj-Format as well as some classic (WPF) projects and in the solution directory I have the follwoing nuget.config file:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <!-- only needed if TFVC is used to prevent nuget from checking in the packages folder -->
  <solution>
    <add key="disableSourceControlIntegration" value="true" />
  </solution>

  <!-- package feeds that should be set for all users of the project -->
  <packageSources>
    <add key="custom1" value="\\some\fileshare\NuGet" />
    <add key="NuGet" value="https://api.nuget.org/v3/index.json" />
    <add key="TFS Feed" value="https://tfs/tfs/Foo/_packaging/myfeed/nuget/v3/index.json" />
  </packageSources>
  
  <config>
    <clear />
    <add key="globalPackagesFolder" value="packages" />
  </config>  
</configuration>

when I run nuget.exe local -list all I get the following output:

http-cache: C:\Users\Me\AppData\Local\NuGet\v3-cache
global-packages: C:\mysolution\packages
temp: C:\Users\Me\AppData\Local\Temp\NuGetScratch
plugins-cache: C:\Users\Me\AppData\Local\NuGet\plugins-cache

When I run nuget.exe restore all packages are correctly restored to the local packages folder in C:\mysolution\packages.

However when I rightclick the solution in the VS 2017 solution explorer, and to "Rebuild Solution" or "Restore NuGet Packages", only the packages referenced by the classic (WPF) projects are being restored to that local packages folder. All packages that are referenced by the .NET Core projects are restored to the global folder in %userprofile%\.nuget\packages

I am desperately trying to find a decent workflow where I can quickly test and update packages in one solution that are being built in another solution during local development. That's the whole purpose of changing the global packages folder. #7678

NuGet product used: VS UI
NuGet version: 4.9.2.0
dotnet.exe --version: 2.2.102
OS version: Win10 v1809

[bitbonk]

OK, it looks like Visual Studio has a problem if the globalPackagesFolder is the same as the local packages folder used by the old project system. If I change it to another folder

<add key="globalPackagesFolder" value="packages2" />

everything works fine. The packages referenced projects of the new project system are correctly restored to packages2 and the other ones to packages.

[nkolev92]

@bitbonk The root of the problem is that the directory structure of the packages folder for PC restore and the global packages folder is different.
What we call V2 vs V3.

packageName.packageVersion
vs
packageName\packageVersion\

NuGet should give a better error message though.