chrome-DebuggerTests failing on 9.0 because of ICU version mismatch

[svick]

Build Information

Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1417017
Build error leg or test failing: chrome-DebuggerTests.AsyncTests.WorkItemExecution
Pull request: #126136

Error Message

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

{
  "ErrorMessage": ["DebuggerTests", "Value for json property named description didn't match."],
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Example failure:

DebuggerTests.DateTimeTestsEFIGS.CheckDateTimeLocale(locale: "en-US", fdtp: "dddd, MMMM d, yyyy h:mm:ss tt", ldp: "dddd, MMMM d, yyyy", ltp: "h:mm:ss tt", sdp: "M/d/yyyy", stp: "h:mm tt") [FAIL]
  Failed DebuggerTests.DateTimeTestsEFIGS.CheckDateTimeLocale(locale: "en-US", fdtp: "dddd, MMMM d, yyyy h:mm:ss tt", ldp: "dddd, MMMM d, yyyy", ltp: "h:mm:ss tt", sdp: "M/d/yyyy", stp: "h:mm tt") [291 ms]
  Error Message:
   Assert.Equal() Failure: [[locals#dt] Value for json property named description didn't match.]

Expected: 1/2/2020 3:04:05 AM
Actual:   1/2/2020 3:04:05 AM
  Stack Trace:
     at DebuggerTests.DebuggerTestBase.AssertEqual(Object expected, Object actual, String label) in /_/src/mono/browser/debugger/DebuggerTestSuite/DebuggerTestBase.cs:line 1315
   at DebuggerTests.DebuggerTestBase.CheckValue(JToken actual_val, JToken exp_val, String label) in /_/src/mono/browser/debugger/DebuggerTestSuite/DebuggerTestBase.cs:line 974
   at DebuggerTests.DebuggerTestBase.CheckDateTime(JToken value, DateTime expected, String label) in /_/src/mono/browser/debugger/DebuggerTestSuite/DebuggerTestBase.cs:line 480
   at DebuggerTests.DebuggerTestBase.CheckCustomType(JToken actual_val, JToken exp_val, String label) in /_/src/mono/browser/debugger/DebuggerTestSuite/DebuggerTestBase.cs:line 833
   at DebuggerTests.DebuggerTestBase.CheckValue(JToken actual_val, JToken exp_val, String label) in /_/src/mono/browser/debugger/DebuggerTestSuite/DebuggerTestBase.cs:line 941
   at DebuggerTests.DebuggerTestBase.CheckProps(JToken actual, Object exp_o, String label, Int32 num_fields, Boolean skip_num_fields_check) in /_/src/mono/browser/debugger/DebuggerTestSuite/DebuggerTestBase.cs:line 927
   at DebuggerTests.DateTimeTestsEFIGS.<>c__DisplayClass1_0.<<CheckDateTimeLocale>b__0>d.MoveNext() in /_/src/mono/browser/debugger/DebuggerTestSuite/DateTimeTests.cs:line 73
--- End of stack trace from previous location ---
   at DebuggerTests.DebuggerTestBase.SendCommandAndCheck(JObject args, String method, String script_loc, Int32 line, Int32 column, String function_name, Func`2 wait_for_event_fn, Func`2 locals_fn, String waitForEvent) in /_/src/mono/browser/debugger/DebuggerTestSuite/DebuggerTestBase.cs:line 710
   at DebuggerTests.DebuggerTestBase.EvaluateAndCheck(String expression, String script_loc, Int32 line, Int32 column, String function_name, Func`2 wait_for_event_fn, Func`2 locals_fn) in /_/src/mono/browser/debugger/DebuggerTestSuite/DebuggerTestBase.cs:line 676
   at DebuggerTests.DateTimeTestsEFIGS.CheckDateTimeLocale(String locale, String fdtp, String ldp, String ltp, String sdp, String stp) in /_/src/mono/browser/debugger/DebuggerTestSuite/DateTimeTests.cs:line 64
--- End of stack trace from previous location ---

The two date strings that look the same apparently aren't: one of them uses a regular space, the other U+202F NARROW NO‑BREAK SPACE. According to Copilot, this was caused by #126527, which updated Ubuntu version from 22.04 to 26.04, bringing in a new version of ICU.

These tests don't exist on main, since they were removed in #114479.

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1417017
Error message validated: [DebuggerTests Value for json property named description didn't match.]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 5/13/2026 10:14:40 AM UTC

Report

Build	Definition	Test	Pull Request
1419784	dotnet/runtime	chrome-DebuggerTests.SteppingTests.WorkItemExecution
1419320	dotnet/runtime	chrome-DebuggerTests.SteppingTests.WorkItemExecution	#128153
1419215	dotnet/runtime	chrome-DebuggerTests.SteppingTests.WorkItemExecution
1419075	dotnet/runtime	chrome-DebuggerTests.SteppingTests.WorkItemExecution
1417017	dotnet/runtime	chrome-DebuggerTests.SteppingTests.WorkItemExecution	#126136
1418849	dotnet/runtime	chrome-DebuggerTests.SteppingTests.WorkItemExecution
1418738	dotnet/runtime	chrome-DebuggerTests.SteppingTests.WorkItemExecution	#128131

Summary

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

[dotnet-policy-service]

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[MihuBot]

I'm a bot. Here are possible related and/or duplicate issues (I may be wrong):

• Space before AM/PM in the en-US locale changed from regular (0x0020) to non-breaking (0x202f) #102220
• DateTime.ToString with different behavior from local machine and Azure DevOps #96335

[akoeplinger]

Affects 8.0 as well in #126058

@pavelsavara should we just backport #114479 ?

[akoeplinger]

Fixed by #128132 and #128133