[Flaky Test] Microsoft.Build.UnitTests.CodeTaskFactoryTests.BuildTaskSimpleCodeFactoryTestExtraUsing

**Flaky-test key** (automated de-duplication — do not edit):
```text
flaky-test-id: Microsoft.Build.UnitTests.CodeTaskFactoryTests.BuildTaskSimpleCodeFactoryTestExtraUsing
```

## Evidence

- **Distinct sources:** 4 (0 PRs, 4 rolling builds on `main`)
- **Rolling build IDs:** [1514373](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1514373), [1517682](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1517682), [1527742](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1527742), [1532844](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1532844)
- **Legs:** FullOnWindows Release
- **Assembly:** `Microsoft.Build.Tasks.UnitTests`
- **First seen:** 2026-07-17 | **Last seen:** 2026-07-30
- **Error hash:** 2f59b830
- **Sample error:** `Assert.True() Failure — Expected: True, Actual: False`

## Action

This test will be quarantined via `[ActiveIssue("")]` (from `Microsoft.DotNet.XUnitV3Extensions`, namespace `Xunit`) until the underlying nondeterminism is fixed. The quarantine pipeline (def 344) will continue gathering pass/fail signal.

**Assembly:** `Microsoft.Build.Tasks.UnitTests`
**Class:** `Microsoft.Build.UnitTests.CodeTaskFactoryTests`
**Method:** `BuildTaskSimpleCodeFactoryTestExtraUsing`
**Source:** `src/Tasks.UnitTests/CodeTaskFactoryTests.cs`

> [!WARNING]
>
> Firewall blocked 2 domains
>
> The following domains were blocked by the firewall during workflow execution:
>
> - `awmgmcpg`
> - `southcentralus0.in.applicationinsights.azure.com`
>> To allow these domains, add them to the `network.allowed` list in your workflow frontmatter:
>
> ```yaml
> network:
> allowed:
> - defaults
> - "awmgmcpg"
> - "southcentralus0.in.applicationinsights.azure.com"
> ```
>
> See [Network Configuration](https://github.github.com/gh-aw/reference/network/) for more information.
>
>

> Generated by [Flaky Test Triage](https://github.com/dotnet/msbuild/actions/runs/30541891245) · sonnet46 · 155.1 AIC · ⌖ 5.48 AIC · ⊞ 14.7K · [◷](https://github.com/search?q=repo%3Adotnet%2Fmsbuild+is%3Aissue+%22gh-aw-workflow-call-id%3A+dotnet%2Fmsbuild%2Fflaky-test-detector.agent%22&type=issues)

Start in src/Tasks.UnitTests/CodeTaskFactoryTests.cs at CodeTaskFactoryTests.BuildTaskSimpleCodeFactoryTestExtraUsing, then review the four linked rolling builds and the Assert.True failure on the FullOnWindows Release leg. Reproduce the test and identify the nondeterministic condition; done means repeated reliable passes without needing the quarantine annotation.

Written by the indexing model from the issue text.