VSTHRD002 and VSTHRD010 - Performance issues?

I would like to share my observation regarding build performance when using the VSTHRD002UseJtfRunAnalyzer and VSTHRD010MainThreadUsageAnalyzer.

Observation

We observe that the build takes significantly longer than expected in a project that uses:

• Microsoft.VisualStudio.Threading.Analyzers
• .NET 10
• EF Core 10 with Code Migrations.

Build duration comparison (with analyzers vs. no analyzers):

dotnet build → ~58 seconds.
dotnet build -p:RunAnalyzers=false → ~10 seconds.

Analyzer timing from MSBuild.exe /v:d /p:reportanalyzer=true shows

Time (s)    %   Analyzer
  668,239   99   Microsoft.VisualStudio.Threading.Analyzers.CSharp, Version=17.14.15.42505, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
  370,871   55      Microsoft.VisualStudio.Threading.Analyzers.VSTHRD010MainThreadUsageAnalyzer (VSTHRD010)
  290,486   43      Microsoft.VisualStudio.Threading.Analyzers.VSTHRD002UseJtfRunAnalyzer (VSTHRD002)
  3,736   <1      Microsoft.VisualStudio.Threading.Analyzers.VSTHRD103UseAsyncOptionAnalyzer (VSTHRD103)
  1,340   <1      Microsoft.VisualStudio.Threading.Analyzers.CSharpVSTHRD110ObserveResultOfAsyncCallsAnalyzer (VSTHRD110)
  1,252   <1      Microsoft.VisualStudio.Threading.Analyzers.CSharpVSTHRD012SpecifyJtfWhereAllowed (VSTHRD012)
  0,196   <1      Microsoft.VisualStudio.Threading.Analyzers.CSharpVSTHRD109AvoidAssertInAsyncMethodsAnalyzer (VSTHRD109)

The two analyzers (VSTHRD010 and VSTHRD002) account for the large majority of analyzer execution time.

Project details

• The EF Core model contains ~100 model entities (SQL Server tables) in a Model project.
• An Entity contains DbContext and 175 database migrations.
• Each migration consist of two files:
  • the migration itself
  • and the "*.Designer.cs" file.
• The designer files in project grow in time from ~60 kB to ~180 kB.
• Total size of designer files in Entity project is 22,16 MB.
• Total size of code files in Entity project is 22,86 MB.

Start with the reported MSBuild analyzer timing and compare dotnet build with dotnet build -p:RunAnalyzers=false in a project containing the described EF Core migrations and large designer files. Investigate VSTHRD010 and VSTHRD002 first; done should mean identifying the source of their disproportionate cost and documenting or validating a concrete improvement.