Microsoft.XmlSerializer.Generator returns warnings with the .NET 6 and 7 SDK

[mcpat-it]

Description

When using the Microsoft.XmlSerializer.Generator NuGet package (v6 and also pre v7), I receive some warnings during compilation.

Reproduction Steps

Can supply simple sample app, but I used the description more or less written here.

Expected behavior

The Microsoft.XmlSerializer.Generator tool generates an optimized assembly for the XmlSerializer without warnings.

Actual behavior

The Microsoft.XmlSerializer.Generator generates warnings:

1>------ Erstellen gestartet: Projekt: xxx, Konfiguration: Debug Any CPU ------
1>xxx-> C:\xxx\bin\Debug\net6.0-windows\xxx.dll
1>.NET Xml Serialization Generation Utility, Version 7.0.0-preview.7.22375.6]
1>SGEN : warning SGEN1: Could not load file or assembly 'PresentationFramework, Version=6.0.2.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. Reference assemblies should not be loaded for execution.  They can only be loaded in the Reflection-only loader context. (0x80131058)
1>SGEN : warning SGEN1: Cannot load a reference assembly for execution.
1>SGEN : warning SGEN1: Could not load file or assembly 'Microsoft.VisualBasic.Forms, Version=6.0.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'. Reference assemblies should not be loaded for execution.  They can only be loaded in the Reflection-only loader context. (0x80131058)
1>SGEN : warning SGEN1: Cannot load a reference assembly for execution.
1>SGEN : warning SGEN1: Could not load file or assembly 'System.Configuration.ConfigurationManager, Version=6.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL'. Reference assemblies should not be loaded for execution.  They can only be loaded in the Reflection-only loader context. (0x80131058)
1>SGEN : warning SGEN1: Cannot load a reference assembly for execution.
1>Serialization Code File Name: C:\xxx\obj\Debug\net6.0-windows\xxx.XmlSerializers.cs.
1>Generated serialization code for assembly C:\xxx\obj\Debug\net6.0-windows\xxx.dll --> 'C:\xxx\obj\Debug\net6.0-windows\xxx.XmlSerializers.cs'.
1>Erstellen des Projekts xxx.csproj beendet.
========== Erstellen: 1 erfolgreich, 0 Fehler, 2 aktuell, 0 übersprungen ==========

Regression?

It's the first time I try the Microsoft.XmlSerializer.Generator tool so I can't say.

Known Workarounds

Add following in csproj file:

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <NoWarn>SGEN1</NoWarn>
</PropertyGroup>

Configuration

dotnet --info
.NET SDK (gemäß "global.json"):
 Version:   7.0.100-preview.7.22377.5
 Commit:    ba310d9309

Laufzeitumgebung:
 OS Name:     Windows
 OS Version:  10.0.19043
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\7.0.100-preview.7.22377.5\

Host:
  Version:      7.0.0-preview.7.22375.6
  Architecture: x64
  Commit:       eecb028078

.NET SDKs installed:
  3.1.408 [C:\Program Files\dotnet\sdk]
  3.1.421 [C:\Program Files\dotnet\sdk]
  5.0.100-rc.1.20452.10 [C:\Program Files\dotnet\sdk]
  5.0.408 [C:\Program Files\dotnet\sdk]
  5.0.411 [C:\Program Files\dotnet\sdk]
  6.0.108 [C:\Program Files\dotnet\sdk]
  6.0.303 [C:\Program Files\dotnet\sdk]
  6.0.400 [C:\Program Files\dotnet\sdk]
  7.0.100-preview.7.22377.5 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.All 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.24 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.24 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.27 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.28 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.0-rc.1.20451.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.0-preview.7.22376.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.24 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.27 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.28 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.0-rc.1.20451.14 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.0-preview.7.22375.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.1.27 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.28 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.0-rc.1.20452.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.8 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.0-preview.7.22377.1 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
  x86   [C:\Program Files (x86)\dotnet]
    registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download

Other information

I can use the generated xxx.XmlSerializers.dll, but this warnings are annoying...

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[Ilchert]

Faced with the same issue in WCF projects. It happens when class has attribute from .net framework assembly.
Simple repro target .net472:

[System.Web.Services.WebServiceBindingAttribute(Name = "...", Namespace = "1")]
public class Class1
{
}

csproj

<Reference Include="System.Web.Services" />
<PackageReference Include="Microsoft.XmlSerializer.Generator" Version="6.0.0" />
<PackageReference Include="System.Memory" Version="4.5.5" />
<DotNetCliToolReference Include="Microsoft.XmlSerializer.Generator" Version="6.0.0" />

Another workaround (thanks to @kant2002) is adding reference to System.Web.Services explicitly from Framework64\v4.0.30319

<SGenReferences>C:\Windows\Microsoft.NET\Framework64\v4.0.30319\System.Web.Services.dll</SGenReferences>