[Flaky Test] Microsoft.Build.UnitTests.CreateItem_Tests.RecursiveDirOutOfProc

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

## Evidence

- **Distinct sources:** 3 (0 PRs + 3 rolling main builds)
- **Rolling builds:** [1496519](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1496519), [1506834](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1506834), [1514373](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1514373)
- **Legs:** FullOnWindows, FullOnWindows Release
- **TFM:** net472
- **Assembly:** Microsoft.Build.Tasks.UnitTests
- **First seen:** 2026-07-07 | **Last seen:** 2026-07-17
- **Error hashes:** 2 distinct (f5611e9d, 1cf607f2) — multiple distinct failure signatures confirm non-determinism
- **Sample build:** [1496519](https://dev.azure.com/dnceng-public/public/_build/results?buildId=1496519)

**Sample error:**
```
Shouldly.ShouldAssertException: result.OverallResult should be BuildResultCode.Success but was BuildResultCode.Failure
```

## Notes

This test will be quarantined via `[ActiveIssue("https://github.com/dotnet/msbuild/issues/")]` (from `Microsoft.DotNet.XUnitV3Extensions`, namespace `Xunit`) until the underlying nondeterminism is fixed.

> [!WARNING]
>
> Firewall blocked 1 domain
>
> The following domain was blocked by the firewall during workflow execution:
>
> - `awmgmcpg`
>> To allow these domains, add them to the `network.allowed` list in your workflow frontmatter:
>
> ```yaml
> network:
> allowed:
> - defaults
> - "awmgmcpg"
> ```
>
> 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/29643670790) · 114.5 AIC · ⌖ 4.91 AIC · ⊞ 13.5K · [◷](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 by locating Microsoft.Build.UnitTests.CreateItem_Tests.RecursiveDirOutOfProc in the Microsoft.Build.Tasks.UnitTests assembly and reproducing it on the FullOnWindows net472 legs, using the linked rolling builds and sample error as evidence. Trace the nondeterministic failure, then confirm the test consistently returns BuildResultCode.Success before removing or resolving the quarantine reference.

Written by the indexing model from the issue text.