[Test Failure] System.Net.Security.Tests.SslStreamTlsResumeTests.DifferentHost_NoResume

[ViveliDuCh]

Build Information

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1569288
Build error leg or test failing: windows-x64 Debug CoreCLR_AllSubsets (windows.server2025.amd64.open.rt) - System.Net.Security.Tests
Pull request: #132794

KBE authoring guidance

• Error Details is for readers. Build Analysis parses only the single JSON block under Error Message.
• ErrorMessage is in array form: each element is matched as a case-sensitive ordinal String.Contains substring, in order, copied verbatim from the failing log.
• BuildRetry is false (deterministic assertion failure, not an infrastructure flake). ExcludeConsoleLog is false.

Error Details

System.Net.Security.Tests.SslStreamTlsResumeTests.DifferentHost_NoResume fails on Windows Server 2025 (x64) for both Tls12 and Tls13. The test expects the TLS session to be resumed (expectResume: true), but resumption did not occur (Actual: False).

System.Net.Security.Tests.SslStreamTlsResumeTests.DifferentHost_NoResume(sslProtocol: Tls12) [FAIL]
  Assert.Equal() Failure: Values differ
  Expected: True
  Actual:   False
  Stack Trace:
    /_/src/libraries/System.Net.Security/tests/FunctionalTests/SslStreamAllowTlsResumeTests.cs(256,0): at System.Net.Security.Tests.SslStreamTlsResumeTests.RunConnectionAsync(SslServerAuthenticationOptions serverOptions, SslClientAuthenticationOptions clientOptions, Nullable`1 expectResume)
    /_/src/libraries/System.Net.Security/tests/FunctionalTests/SslStreamAllowTlsResumeTests.cs(401,0): at System.Net.Security.Tests.SslStreamTlsResumeTests.TestNoResumeAfterChange(SslServerAuthenticationOptions serverOptions, SslClientAuthenticationOptions clientOptions, Action`2[] updateOptions)
    --- End of stack trace from previous location ---

System.Net.Security.Tests.SslStreamTlsResumeTests.DifferentHost_NoResume(sslProtocol: Tls13) [FAIL]
  Assert.Equal() Failure: Values differ
  Expected: True
  Actual:   False
  Stack Trace:
    (identical to the Tls12 case above)

Error Message

{
  "ErrorMessage": [
    "System.Net.Security.Tests.SslStreamTlsResumeTests.DifferentHost_NoResume",
    "Assert.Equal() Failure: Values differ",
    "Expected: True",
    "Actual:   False"
  ],
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

KBE verification

Filed manually via the create-kbe skill (not the scheduled ci-failure-scan).
Artifact kind: kbe-verification
Verified match count: 2 hits per array element in the failing System.Net.Security.Tests console log (Tls12 + Tls13 cases). The test name appears only on [FAIL] lines, with no [PASS]/[SKIP] matches.
Failing build finished: 2026-08-27T17:29:35Z (after the console log was produced).

Note

This issue was created with the assistance of GitHub Copilot.

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1569288
Error message validated: [System.Net.Security.Tests.SslStreamTlsResumeTests.DifferentHost_NoResume Assert.Equal() Failure: Values differ Expected: True Actual: False]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 8/27/2026 7:27:41 PM UTC

Report

Build	Repository	Test	Pull Request
1574202	dotnet/runtime	System.Net.Security.Tests.SslStreamTlsResumeTests.DifferentHost_NoResume	#132953
1573798	dotnet/runtime	System.Net.Security.Tests.SslStreamTlsResumeTests.DifferentHost_NoResume	#132923
1573200	dotnet/runtime	System.Net.Security.Tests.SslStreamTlsResumeTests.DifferentHost_NoResume	#132908
1572950	dotnet/runtime	System.Net.Security.Tests.SslStreamTlsResumeTests.DifferentHost_NoResume	#132899
1569288	dotnet/runtime	System.Net.Security.Tests.SslStreamTlsResumeTests.DifferentHost_NoResume	#132794

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
1	5	5

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