[ci-scan] Test failure: PolymorphicTests.MetadataServices_NullPolymorphismOptions_DoesNotActivateAttributeClassifier on tvOS

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Build Information

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1438268
Build error leg or test failing: tvos-arm64 Release AllSubsets_Mono - System.Text.Json.Tests

Error Details

[FAIL] System.Text.Json.Serialization.Tests.PolymorphicTests_String.MetadataServices_NullPolymorphismOptions_DoesNotActivateAttributeClassifier
Error:      Assert.Equal() Failure: Values differ
            Expected: typeof(System.Text.Json.Serialization.Tests.PolymorphicTests+AttrClassifiedDog)
            Actual:   typeof(System.Text.Json.Serialization.Tests.PolymorphicTests+AttrClassifiedCat)

Multiple variants affected: PolymorphicTests_String, PolymorphicTests_Pipe, PolymorphicTests_Node, PolymorphicTests_Document, PolymorphicTests_SyncStream, PolymorphicTests_AsyncStreamWithSmallBuffer, PolymorphicTests_Span, PolymorphicTests_Element, PolymorphicTests_AsyncStream, PolymorphicTests_Writer.

Error Message

true only for clear infra flakes. ExcludeConsoleLog skips helix log scanning. -->

{
  "ErrorMessage": ["MetadataServices_NullPolymorphismOptions_DoesNotActivateAttributeClassifier", "Expected: typeof(System.Text.Json.Serialization.Tests.PolymorphicTests+AttrClassifiedDog)"],
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Impact on platforms

• runtime-extra-platforms (def 154) / tvos-arm64 Release AllSubsets_Mono / System.Text.Json.Tests / Exit code 1
• Occurrences in window: 3+ (builds 1436493, 1438268, 1440191)

First build it occurred

• Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1433744
• Finished: 2026-05-25T09:02:27Z
• Persistent across the entire scanned window; true origin may predate 2026-05-24.

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Filed by ci-failure-scan, which scans dnceng-public outer-loop pipelines on main and converts stable failures into KBEs and test-disable PRs.

Generated by CI Outer-Loop Failure Scanner · ● 16.3M · ◷

Report

Build	Repository	Test	Pull Request
1447125	dotnet/runtime	System.Text.Json.Tests.WorkItemExecution

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
0	0	1

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Tagging subscribers to 'os-ios': @vitek-karas, @kotlarmilos, @steveisok, @akoeplinger
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Tagging subscribers to this area: @dotnet/area-system-text-json
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