Quarantine BlazorWebTemplateTest.BlazorWebTemplate_Works

[github-actions]

Failing Test(s)

BlazorTemplates.Tests.BlazorWebTemplateTest.BlazorWebTemplate_Works

Error Message

Tests failed: Templates.Blazor.Tests_net11.0_x64.html [net11.0|x64]
(Error messages not available in AzDO test results for this non-Helix test run)

Stacktrace

Stack Trace

Not available - test runs locally on Windows agent without Helix console log capture.
Previous similar failures (issues #66292, #66293) showed:
   at Templates.Test.Helpers.Project.RunDotNetNewAsync(String templateName, ...) in Project.cs
   at BlazorTemplates.Tests.BlazorTemplateTest.CreateBuildPublishAsync(...)

Logs

Console log

BlazorWebTemplate_Works - Failed (all InlineData variants)

All template tests in build 1388488 fail together, strongly suggesting
a template infrastructure issue (same pattern as NU1603 DevServer version
resolution failures tracked in #66292 and #66293).

Build

https://dev.azure.com/dnceng-public/public/_build/results?buildId=1388488

Also failed in build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1363350

Generated by Daily Test Quarantine Management · ● 6.7M · ◷

[github-actions]

Investigation

BlazorWebTemplate_Works has failed in at least 2 CI builds on main:

• Build 1388488 (2026-04-21) — all Blazor template tests fail together
• Build 1363350 (2026-04-02)

Pattern Analysis

In build 1388488, ALL Blazor template test classes fail simultaneously:

• BlazorWebTemplateTest.BlazorWebTemplate_Works
• WebWorkerTemplateE2ETest.* (4 methods)
• BlazorWasmTemplateTest.* (3 methods)

This pattern — multiple distinct test classes failing together in a Windows agent run — is characteristic of a shared template test infrastructure issue rather than individual test bugs. The same scenario was previously diagnosed as an NU1603 NuGet restore failure where Microsoft.AspNetCore.Components.WebAssembly.DevServer 11.0.0-ci was not found and a preview version was resolved instead (tracked in #66292 and #66293).

A fix was attempted in #66303 (DevServer version pin fix), but the tests continue to fail after that fix landed, suggesting either the fix is not fully effective in all build environments or a new preview package has reintroduced the condition.

Recommendation

Investigate whether the DevServer version pin introduced in #66303 is correctly applied in the Windows CI agent environment. Check NuGet restore logs in the failing build to confirm whether NU1603 is still occurring.

Generated by Daily Test Quarantine Management · ● 6.7M · ◷