[ci-scan] Test failure: System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries

## Build Information
Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1577452
Build error leg or test failing: net11.0-linux-Debug-x64-coreclr_release-Ubuntu.2604.Amd64.Open-System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries
Pull request: https://github.com/dotnet/runtime/pull/133027

KBE authoring guidance (ci-failure-scan)

- `Error Details` is for readers. The exception and stack trace below make the failure understandable without opening the raw log.
- Build Analysis parses only the single JSON block under `Error Message`.
- `ErrorMessage` contains case-sensitive ordinal `String.Contains` substrings copied verbatim from the failing log.
- `BuildRetry` is false because this is a test failure rather than a clear infrastructure retry case.

## Error Details

```
System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries [FAIL]
System.Net.Http.HttpRequestException : The request was aborted.
Stack Trace:
/_/src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http3Connection.cs(331,0): at System.Net.Http.Http3Connection.SendAsync(HttpRequestMessage request, WaitForHttp3ConnectionActivity waitForConnectionActivity, Boolean streamAvailable, CancellationToken cancellationToken)
/_/src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http3Connection.cs(357,0): at System.Net.Http.Http3Connection.SendAsync(HttpRequestMessage request, WaitForHttp3ConnectionActivity waitForConnectionActivity, Boolean streamAvailable, CancellationToken cancellationToken)
/_/src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/ConnectionPool/HttpConnectionPool.Http3.cs(108,0): at System.Net.Http.HttpConnectionPool.TrySendUsingHttp3Async(HttpRequestMessage request, CancellationToken cancellationToken)
/_/src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/ConnectionPool/HttpConnectionPool.cs(441,0): at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)
/_/src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/RedirectHandler.cs(29,0): at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
/_/src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpMessageHandlerStage.cs(21,0): at System.Net.Http.HttpMessageHandlerStage.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
/_/src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/SocketsHttpHandler.cs(704,0): at System.Net.Http.SocketsHttpHandler.g__CreateHandlerAndSendAsync|122_0(HttpRequestMessage request, CancellationToken cancellationToken)
/_/src/libraries/System.Net.Http/src/System/Net/Http/HttpClient.cs(544,0): at System.Net.Http.HttpClient.g__Core|83_0(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationTokenSource cts, Boolean disposeCts, CancellationTokenSource pendingRequestsCts, CancellationToken originalCancellationToken)
/_/src/libraries/System.Net.Http/src/System/Net/Http/HttpClient.cs(524,0): at System.Net.Http.HttpClient.SendAsync(HttpRequestMessage request, HttpCompletionOption completionOption)
/_/src/libraries/System.Net.Http/tests/FunctionalTests/HttpClientHandlerTest.Http3.cs(420,0): at System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.<>c__DisplayClass11_0.b__1()
/_/src/libraries/Common/tests/System/Threading/Tasks/TaskTimeoutExtensions.cs(119,0): at System.Threading.Tasks.TaskTimeoutExtensions.GetRealException(Task task)
/_/src/libraries/Common/tests/System/Threading/Tasks/TaskTimeoutExtensions.cs(89,0): at System.Threading.Tasks.TaskTimeoutExtensions.WhenAllOrAnyFailed(Task[] tasks)
/_/src/libraries/Common/tests/System/Threading/Tasks/TaskTimeoutExtensions.cs(54,0): at System.Threading.Tasks.TaskTimeoutExtensions.WhenAllOrAnyFailed(Task[] tasks, Int32 millisecondsTimeout)
/_/src/libraries/System.Net.Http/tests/FunctionalTests/HttpClientHandlerTest.Http3.cs(423,0): at System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries()
```

This test also appeared in the historical HTTP/3 retry tracker #91017, which was closed in 2024 and did not contain a Build Analysis signature.

## Error Message

```json
{
"ErrorMessage": [
"System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries [FAIL]",
"System.Net.Http.HttpRequestException : The request was aborted."
],
"ErrorPattern": "",
"BuildRetry": false,
"ExcludeConsoleLog": false
}
```

Agentic workflow metadata (ci-failure-scan)

Workflow artifact: ci-failure-scan
Artifact kind: kbe-verification
Verified match count: 1 hits in failure.log

> [!NOTE]
> This issue was drafted and filed with assistance from GitHub Copilot.

### Known issue validation
**Build: :mag_right:** https://dev.azure.com/dnceng-public/public/_build/results?buildId=1577452
**Error message validated:** `[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries [FAIL] System.Net.Http.HttpRequestException : The request was aborted.`]
**Result validation:** :white_check_mark: Known issue matched with the provided build.
**Validation performed at:** 9/2/2026 1:59:44 AM UTC

### Report

|Build|Repository|Test|Pull Request|
|---|---|---|---|
|[1597340](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597340)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1597340&view=ms.vss-test-web.build-test-results-tab&runId=44098798&resultId=229400)|dotnet/runtime#133940|
|[1596986](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596986)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596986&view=ms.vss-test-web.build-test-results-tab&runId=44085924&resultId=150064)||
|[1596309](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596309)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596309&view=ms.vss-test-web.build-test-results-tab&runId=44068842&resultId=223264)|dotnet/runtime#133773|
|[1596321](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596321)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596321&view=ms.vss-test-web.build-test-results-tab&runId=44069022&resultId=188955)||
|[1596210](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596210)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1596210&view=ms.vss-test-web.build-test-results-tab&runId=44067960&resultId=208265)|dotnet/runtime#133188|
|[1595880](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595880)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595880&view=ms.vss-test-web.build-test-results-tab&runId=44060574&resultId=208004)|dotnet/runtime#133885|
|[1595672](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595672)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595672&view=ms.vss-test-web.build-test-results-tab&runId=44056392&resultId=218035)|dotnet/runtime#131652|
|[1595611](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595611)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595611&view=ms.vss-test-web.build-test-results-tab&runId=44055338&resultId=221219)|dotnet/runtime#133606|
|[1595428](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595428)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595428&view=ms.vss-test-web.build-test-results-tab&runId=44049190&resultId=209093)|dotnet/runtime#133853|
|[1595348](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595348)|dotnet/runtime|[System.Net.Http.Functional.Tests.SocketsHttpHandlerTest_Cookies_Http3.GetAsync_Redirect_CookiesArePreserved](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1595348&view=ms.vss-test-web.build-test-results-tab&runId=44048706&resultId=211125)|dotnet/runtime#129683|
|[1594516](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594516)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594516&view=ms.vss-test-web.build-test-results-tab&runId=44015810&resultId=214336)|dotnet/runtime#133662|
|[1594311](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594311)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1594311&view=ms.vss-test-web.build-test-results-tab&runId=44009910&resultId=216526)||
|[1593988](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1593988)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1593988&view=ms.vss-test-web.build-test-results-tab&runId=43998700&resultId=195136)|dotnet/runtime#130050|
|[1593583](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1593583)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1593583&view=ms.vss-test-web.build-test-results-tab&runId=43987178&resultId=215161)|dotnet/runtime#133734|
|[1593470](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1593470)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1593470&view=ms.vss-test-web.build-test-results-tab&runId=43984106&resultId=215073)||
|[1593453](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1593453)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1593453&view=ms.vss-test-web.build-test-results-tab&runId=43983202&resultId=214095)||
|[1592471](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1592471)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1592471&view=ms.vss-test-web.build-test-results-tab&runId=43960374&resultId=227397)|dotnet/runtime#133595|
|[1592224](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1592224)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1592224&view=ms.vss-test-web.build-test-results-tab&runId=43952438&resultId=228238)|dotnet/runtime#133494|
|[1592076](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1592076)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1592076&view=ms.vss-test-web.build-test-results-tab&runId=43946306&resultId=209406)|dotnet/runtime#133664|
|[1591427](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1591427)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1591427&view=ms.vss-test-web.build-test-results-tab&runId=43929714&resultId=208864)|dotnet/runtime#130050|
|[1591177](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1591177)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1591177&view=ms.vss-test-web.build-test-results-tab&runId=43923586&resultId=185544)||
|[1591048](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1591048)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1591048&view=ms.vss-test-web.build-test-results-tab&runId=43920954&resultId=197025)|dotnet/runtime#133605|
|[1590905](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1590905)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1590905&view=ms.vss-test-web.build-test-results-tab&runId=43916676&resultId=231307)|dotnet/runtime#130407|
|[1590326](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1590326)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1590326&view=ms.vss-test-web.build-test-results-tab&runId=43895818&resultId=229091)||
|[1589850](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1589850)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1589850&view=ms.vss-test-web.build-test-results-tab&runId=43885022&resultId=216438)|dotnet/runtime#132687|
|[1588088](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1588088)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1588088&view=ms.vss-test-web.build-test-results-tab&runId=43828486&resultId=217481)||
|[1588007](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1588007)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1588007&view=ms.vss-test-web.build-test-results-tab&runId=43827668&resultId=209755)|dotnet/runtime#133451|
|[1587751](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1587751)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1587751&view=ms.vss-test-web.build-test-results-tab&runId=43817938&resultId=215265)|dotnet/runtime#133116|
|[1587371](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1587371)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1587371&view=ms.vss-test-web.build-test-results-tab&runId=43808204&resultId=197504)|dotnet/runtime#133378|
|[1585519](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1585519)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1585519&view=ms.vss-test-web.build-test-results-tab&runId=43749400&resultId=232418)||
|[1585080](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1585080)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1585080&view=ms.vss-test-web.build-test-results-tab&runId=43735938&resultId=214891)||
|[1583239](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583239)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1583239&view=ms.vss-test-web.build-test-results-tab&runId=43681690&resultId=195146)|dotnet/runtime#133000|
|[1582118](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1582118)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1582118&view=ms.vss-test-web.build-test-results-tab&runId=43646550&resultId=230860)||
|[1581869](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1581869)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1581869&view=ms.vss-test-web.build-test-results-tab&runId=43637218&resultId=222181)|dotnet/runtime#132419|
|[1581252](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1581252)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1581252&view=ms.vss-test-web.build-test-results-tab&runId=43626784&resultId=217631)|dotnet/runtime#132908|
|[1580255](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1580255)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1580255&view=ms.vss-test-web.build-test-results-tab&runId=43585068&resultId=217906)||
|[1579842](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1579842)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1579842&view=ms.vss-test-web.build-test-results-tab&runId=43572516&resultId=215644)|dotnet/runtime#132861|
|[1579649](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1579649)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1579649&view=ms.vss-test-web.build-test-results-tab&runId=43568150&resultId=241361)|dotnet/runtime#133128|
|[1577318](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1577318)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1577318&view=ms.vss-test-web.build-test-results-tab&runId=43500134&resultId=225387)|dotnet/runtime#132978|
|[1577452](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1577452)|dotnet/runtime|[System.Net.Http.Functional.Tests.HttpClientHandlerTest_Http3.SendAsync_RequestRejected_ClientRetries](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1577452&view=ms.vss-test-web.build-test-results-tab&runId=43490818&resultId=228188)|dotnet/runtime#133027|
#### Summary
|24-Hour Hit Count|7-Day Hit Count|1-Month Count|
|---|---|---|
|8|29|40|