Build performance degradation caused by Microsoft.Extensions.Validation.ValidationsGenerator

[JakubLinhart]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

After migrating a large C# solution (approximately 1.2M lines of code) from .NET 8 to .NET 10, we observed a significant build slowdown:

• .NET 8 build time: ~3 minutes
• .NET 10 build time: ~8 minutes

The slowdown appears to be partly caused by the Microsoft.Extensions.Validation.ValidationsGenerator source generator:

git clean -dxf
dotnet restore src
dotnet build src /p:ReportAnalyzer=true /bl --no-restore

produces this:

• This issue seems related to Performance regression when running analyzers with .NET 10 roslyn#80756.
• Our solution does not directly or indirectly reference Microsoft.Extensions.Validation.
• Despite this, the Microsoft.Extensions.Validation.ValidationsGenerator source generator is still executed during the build and contributes to the performance degradation.

Expected Behavior

Microsoft.Extensions.Validation.ValidationsGenerator is not executed when a project doesn't reference Microsoft.Extensions.Validation package.

Steps To Reproduce

No response

Exceptions (if any)

No response

.NET Version

10.0.100

Anything else?

Host:
  Version:      10.0.0
  Architecture: x64
  Commit:       b0f34d51fc

.NET SDKs installed:
  8.0.416 [C:\Program Files\dotnet\sdk]
  9.0.205 [C:\Program Files\dotnet\sdk]
  9.0.306 [C:\Program Files\dotnet\sdk]
  10.0.100 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 8.0.21 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 8.0.22 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 9.0.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 9.0.10 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 10.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 8.0.21 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 8.0.22 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 9.0.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 9.0.10 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 10.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 8.0.21 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 8.0.22 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 9.0.6 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 9.0.10 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 10.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

[javiercn]

@JakubLinhart thanks for contacting us.

The validation source generator is included as part of the framework reference to asp.net core.

@captainsafia any thoughts here?

[JakubLinhart]

Btw. we are using this workaround to "disable" the generator:

  <Target Name="RemoveUnwantedGenerator" BeforeTargets="CoreCompile">
    <ItemGroup>
        <Analyzer Remove="@(Analyzer)" Condition="%(Analyzer.FileName) == 'Microsoft.Extensions.Validation.ValidationsGenerator'" />
    </ItemGroup>
  </Target>