dotnet format is constantly failing on CI

[Kielek]

dotnet format .\OpenTelemetry.AutoInstrumentation.sln --no-restore --verify-no-changes
  dotnet format .\OpenTelemetry.AutoInstrumentation.sln --no-restore --verify-no-changes
  shell: C:\Program Files\PowerShell\7\pwsh.EXE -command ". '{0}'"
  env:
    DOTNET_ROOT: C:\Program Files\dotnet
Unhandled exception: System.Exception: The build host could not be found at 'C:\Program Files\dotnet\sdk\9.0.100\DotnetTools\dotnet-format\BuildHost-net47[2](https://github.com/open-telemetry/opentelemetry-dotnet-instrumentation/actions/runs/12113589586/job/33768778492?pr=3840#step:4:2)\Microsoft.CodeAnalysis.Workspaces.MSBuild.BuildHost.exe'
   at Microsoft.CodeAnalysis.MSBuild.BuildHostProcessManager.AssertBuildHostExists(String buildHostPath)
   at Microsoft.CodeAnalysis.MSBuild.BuildHostProcessManager.GetDotNetFrameworkBuildHostPath()
   at Microsoft.CodeAnalysis.MSBuild.BuildHostProcessManager.CreateDotNetFrameworkBuildHostStartInfo()
   at Microsoft.CodeAnalysis.MSBuild.BuildHostProcessManager.GetBuildHostAsync(BuildHostProcessKind buildHostKind, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.MSBuild.BuildHostProcessManager.GetBuildHostWithFallbackAsync(BuildHostProcessKind buildHostKind, String projectOrSolutionFilePath, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildProjectLoader.Worker.LoadProjectFileInfosAsync(String projectPath, DiagnosticReportingOptions reportingOptions, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildProjectLoader.Worker.LoadProjectInfosFromPathAsync(String projectPath, DiagnosticReportingOptions reportingOptions, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildProjectLoader.Worker.LoadAsync(CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildProjectLoader.LoadSolutionInfoAsync(String solutionFilePath, IProgress`1 progress, ILogger msbuildLogger, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildProjectLoader.LoadSolutionInfoAsync(String solutionFilePath, IProgress`1 progress, ILogger msbuildLogger, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.MSBuild.MSBuildWorkspace.OpenSolutionAsync(String solutionFilePath, ILogger msbuildLogger, IProgress`1 progress, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.Tools.Workspaces.MSBuildWorkspaceLoader.LoadAsync(String solutionOrProjectPath, WorkspaceType workspaceType, String binaryLogPath, Boolean logWorkspaceWarnings, ILogger logger, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.Tools.CodeFormatter.OpenMSBuildWorkspaceAsync(String solutionOrProjectPath, WorkspaceType workspaceType, Boolean noRestore, Boolean requiresSemantics, String binaryLogPath, Boolean logWorkspaceWarnings, ILogger logger, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.Tools.CodeFormatter.FormatWorkspaceAsync(FormatOptions formatOptions, ILogger logger, CancellationToken cancellationToken, String binaryLogPath)
   at Microsoft.CodeAnalysis.Tools.FormatCommandCommon.FormatAsync(FormatOptions formatOptions, ILogger`1 logger, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.Tools.Commands.RootFormatCommand.FormatCommandDefaultHandler.InvokeAsync(ParseResult parseResult, CancellationToken cancellationToken)
   at System.CommandLine.Invocation.InvocationPipeline.InvokeAsync(ParseResult parseResult, CancellationToken cancellationToken)

[Kielek]

It can be reproduced locally on my machine. I have checked, the mentioned exe file is not available, but Microsoft.CodeAnalysis.Workspaces.MSBuild.BuildHost.exe.config is available in the folder.

Similar issues found on GH: dotnet/sdk#44893, dotnet/sdk#43017

[Kielek]

Blocked by dotnet/sdk#45291. It should be included within one of the next .NET9 releases.