[Crossgen2 CI] TestReadyToRun_RuntimeAsync_Libraries build failures on ARM64 platforms

[github-actions]

Failure Details

• Pipeline: runtime-coreclr crossgen2
• Build: 1392560
• Failed Jobs:
  • windows-arm64 Release TestReadyToRun_RuntimeAsync_Libraries — Build product failure
  • linux-arm64 Release TestReadyToRun_RuntimeAsync_Libraries — Test failures (Helix)
  • osx-arm64 Release TestReadyToRun_RuntimeAsync_Libraries — Test failures (Helix)
• Error Category: build-error / test-failure

Failing Jobs

Job Name	Platform	Error Type
windows-arm64 Release TestReadyToRun_RuntimeAsync_Libraries	windows-arm64	Build product failure
linux-arm64 Release TestReadyToRun_RuntimeAsync_Libraries	linux-arm64	Test failure (Helix)
osx-arm64 Release TestReadyToRun_RuntimeAsync_Libraries	osx-arm64	Test failure (Helix)

Error Output

The TestReadyToRun_RuntimeAsync_Libraries jobs compile and test .NET libraries with ReadyToRun (R2R) compilation using RuntimeAsync mode. These jobs are failing on all three ARM64 platforms in the crossgen2 pipeline.

Error details — windows-arm64

Job: windows-arm64 Release TestReadyToRun_RuntimeAsync_Libraries
Failed task: Build product
Log: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1392560&view=logs&j=8e825c52-ff47-5bb5-385b-e1a676a95f95&t=fb4fb41a-19b9-594b-cb8e-1b9447ecc763
(No specific errors extracted from log — the Build product step failed without a clear error message)
```

</details>

<details>
<summary><b>Error details — linux-arm64 and osx-arm64</b></summary>

```
linux-arm64: Work item failures reported via Helix (details truncated in CI analysis output)
osx-arm64: Work item failures reported via Helix (details truncated in CI analysis output)

These jobs failed during Helix test execution. The linux-arm64 job included
Microsoft.Extensions.Hosting.Unit.Tests failures (see related issue `#52`).

Recommended Action

This failure requires deeper investigation. The TestReadyToRun_RuntimeAsync_Libraries jobs test libraries compiled with R2R in RuntimeAsync mode, which is a newer feature. The build product failure on windows-arm64 suggests the R2R compilation itself may be failing for ARM64 targets in RuntimeAsync mode.

Please investigate:

1. Check the full build log for the windows-arm64 job to identify the actual build error
2. Determine if this is a crossgen2 RuntimeAsync-specific issue on ARM64
3. If the root cause cannot be quickly identified, consider disabling the TestReadyToRun_RuntimeAsync_Libraries jobs for ARM64 platforms in the crossgen2 pipeline configuration

Generated by Crossgen2 CI Failure Triage · ◷

• expires on May 23, 2026, 2:56 PM UTC

[github-actions]

Recurrence

This failure was observed again in a recent build:

• Pipeline: runtime-coreclr crossgen2
• Build: 1394465
• Failed jobs:
  • windows-arm64 Release TestReadyToRun_RuntimeAsync_Libraries — Build product failure (same as before)
  • linux-arm64 Release TestReadyToRun_RuntimeAsync_Libraries — Helix test failures
  • osx-arm64 Release TestReadyToRun_RuntimeAsync_Libraries — Helix test failures (HostBuilderTests)

The ARM64 TestReadyToRun_RuntimeAsync_Libraries jobs continue to fail.

Generated by Crossgen2 CI Failure Triage · ◷