Nuget doesn't restore packages for solution, but works when executed for .csproj

Question

I've got a legacy project with a somehow faulty configuration for the used nuget packages.

When I try to restore packages with the solution (.sln) the restore doesn't restore anything. Also, the nuget package manager shows no installed packages for the solution. What I tried:

nuget restore the_solution.sln -MSBuildPath "C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\MSBuild\15.0\Bin" -Verbosity detailed -ConfigFile "C:\Users\jenkins\AppData\Roaming\NuGet\NuGet.Config"

But when I restore the packages for each project (.csproj) the restore works fine and the project can be built. The command I call for the project restore is:

nuget restore path_to_project\packages.config -MSBuildPath "C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\MSBuild\15.0\Bin" -Verbosity detailed  -OutputDirectory "Packages" -ConfigFile "C:\Users\jenkins\AppData\Roaming\NuGet\NuGet.Config"

The packages config for each .csproj looks like this:

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Autofac" version="4.7.0" targetFramework="net461" />
  <!- many other packages -->
</packages>

The .csproj file looks like this:

  <ItemGroup>
    <Reference Include="Autofac, Version=4.7.0.0, Culture=neutral, PublicKeyToken=17863af14b0044da, processorArchitecture=MSIL">
      <HintPath>..\packages\Autofac.4.7.0\lib\net45\Autofac.dll</HintPath>
    </Reference>
<!- many other packages -->

The RestoreProject Style in the .csproj is set to:

  <PropertyGroup>
      <RestoreProjectStyle>PackageReference</RestoreProjectStyle>
  </PropertyGroup>

I have no clue, why I can't use the .sln file for the nuget restore. So, any hint what might causes the error is highly appreciated.

Answer 1

You are using packages in old packages.config format, but restore is set to new packageReference format. Try to remove this line from csproj file

<PropertyGroup>
    <RestoreProjectStyle>PackageReference</RestoreProjectStyle>
</PropertyGroup>

and run restore again at solution level