A recent change to the syntax to support var patterns caused SemanticClassifierTests to fail in the features/recursive-patterns branch (during CI tests). They are skipped with this bug ID.
Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Classification.SemanticClassifierTests.TestVarInPattern1
Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Classification.SemanticClassifierTests.TestVarInPattern2