[release/8.0] TimeZoneInfoTests.Platform_TimeZoneNames failing on Android

[tarekgh]

Build Information

Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1101363
Build error leg or test failing: System.Tests.TimeZoneInfoTests.Platform_TimeZoneNames
Pull request: #117873

https://dev.azure.com/dnceng-public/public/_build/results?buildId=1101363&view=ms.vss-test-web.build-test-results-tab&runId=30146292&resultId=108183&paneView=dotnet-dnceng.dnceng-build-release-tasks.helix-test-information-tab

      <test name="System.Tests.TimeZoneInfoTests.Platform_TimeZoneNames(tzi: (UTC+10:00) Australian Eastern Time (Sydney), displayName: \&quot;(UTC+10:00) Eastern Australia Time (Sydney)\&quot;, alternativeDisplayName: null, standardName: \&quot;Australian Eastern Standard Time\&quot;, daylightName: \&quot;Australian Eastern Daylight Time\&quot;, alternativeDaylightName: null)" type="System.Tests.TimeZoneInfoTests" method="Platform_TimeZoneNames" time="0.0006074" result="Fail">
        <failure exception-type="Xunit.Sdk.TrueException">
          <message><![CDATA[Display Name: Neither '(UTC+10:00) Eastern Australia Time (Sydney)' nor '' equal to '(UTC+10:00) Australian Eastern Time (Sydney)']]></message>
          <stack-trace><![CDATA[   at System.Tests.TimeZoneInfoTests.Platform_TimeZoneNames(TimeZoneInfo tzi, String displayName, String alternativeDisplayName, String standardName, String daylightName, String alternativeDaylightName) in /_/src/libraries/System.Runtime/tests/System.Runtime.Tests/System/TimeZoneInfoTests.cs:line 151
   at System.Object.InvokeStub_TimeZoneInfoTests.Platform_TimeZoneNames(Object , Span`1 )
   at System.Reflection.MethodBaseInvoker.InvokeWithManyArgs(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)]]></stack-trace>
        </failure>
      </test>

Error Message

Fill the error message using step by step known issues guidance.

{
  "ErrorMessage": "Display Name: Neither '(UTC+10:00) Eastern Australia Time (Sydney)' nor '' equal to '(UTC+10:00) Australian Eastern Time (Sydney)'",
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1101363
Error message validated: [Display Name: Neither '(UTC+10:00) Eastern Australia Time (Sydney)' nor '' equal to '(UTC+10:00) Australian Eastern Time (Sydney)']
Result validation: ❌ Known issue did not match with the provided build.
Validation performed at: 7/21/2025 11:13:19 PM UTC

Report

Build	Definition	Test	Pull Request
1146546	dotnet/runtime	System.Runtime.Tests.WorkItemExecution
1145614	dotnet/runtime	System.Runtime.Tests.WorkItemExecution
1131360	dotnet/runtime	System.Runtime.Tests.WorkItemExecution

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
0	1	3

[tarekgh]

CC @matouskozak

[matouskozak]

I see that it is happening on release/9.0-staging as well and I'm not aware of any globalization changes backported to .NET 9 from our side. @kotlarmilos are you aware of any Android OS updates going on?

[kotlarmilos]

No, I am not aware of any Android OS updates.

[akoeplinger]

it's possible that something updated ICU/TZ data on the devices, e.g. through Google Play

[tarekgh]

Usually we get the TZ display names from ICU, so @akoeplinger highly likely be correct.