Skipping restore for project 'SetupWix.wixproj'. The project file may be invalid or missing targets required for restore (NU1503)

Question

We are using Wixtoolset V3.9 to build our setup. We use the following command to start a build:

"C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\MSBuild\Current\Bin\msbuild.exe" /restore /t:Rebuild /p:Configuration=Release /p:Platform=x64 MySolution.sln /p:BabelEnabled=true

Answer 1

TL;DR

You can get rid of NU1503 by including this in your .proj / msbuild file:

  <!-- prevents NU1503 -->
  <Target Name="_IsProjectRestoreSupported"
          Returns="@(_ValidProjectsForRestore)">
    <ItemGroup>
      <_ValidProjectsForRestore Include="$(MSBuildProjectFullPath)" />
    </ItemGroup>
  </Target>
  <Target Name="Restore" />

Source: https://github.com/NuGet/NuGet.Client/blob/537630019c99fdc7bed1b3dfdade72fc3e31692f/src/NuGet.Core/NuGet.Build.Tasks/NuGet.targets#L1286-L1298

---

Detailed explanation

I figured this out by inspecting the msbuild.binlog file via dotnet restore /bl with the awesome MSBuild Binary Log File Viewer tool.

1. The warning is generated by the WarnForInvalidProjectTask :

2. ... which are generated by the _FilterRestoreGraphProjectInputItems target ...

3. ... which calls a _IsProjectRestoreSupported target , if there is one.