[ci-scan] Test failure: GC/Regressions/v2.0-rtm/544701 NativeAOT allocation failure

[github-actions]

Build Information

Build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1532833&view=results
Build error leg or test failing: linux-x64 Checked NativeAOT_Pri1 - GC/Regressions/v2.0-rtm/544701/544701/544701.dll

Error Details

The GC regression test 544701 fails under NativeAOT with an unexpected exception during a large allocation on the runtime-nativeaot-outerloop pipeline (definition 265). The failure reproduces on the source build (1532833, finished 2026-07-30 15:02) and the following completed build (1533287) across the linux x64 / arm64 NativeAOT legs.

This is a post-close recurrence of the previously-filed KBE #131529, which was closed 2026-07-30 09:19; the signature reproduces again in builds that finished after that close. The sibling tests 445488 and 460373 (also System.OutOfMemoryException) were seen only in the source build and not the follow-up, so this KBE is scoped to the persisting 544701 signature.

Running test: GC/Regressions/v2.0-rtm/544701/544701/544701.dll
Unexpected Exception when allocating 41938869 bytes.
Test Failed
Xunit.Sdk.EqualException: Assert.Equal() Failure: Values differ
Expected: 100
Actual:   -1
Failed test: GC/Regressions/v2.0-rtm/544701/544701/544701.dll

Related: #131529

Error Message

{
  "ErrorMessage": "",
  "ErrorPattern": [
    "Running test: GC.Regressions.v2.0-rtm.*544701.dll",
    "Unexpected Exception when allocating 41938869 bytes.",
    "Failed test: GC.Regressions.v2.0-rtm.*544701.dll"
  ],
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

---

Filed by ci-failure-scan (detection only). ci-failure-fix walks open [ci-scan] KBEs and either opens a small fix PR or comments here to loop in owners — it never disables the test.

Note

This issue was generated by an AI agent (Copilot-based CI failure scan workflow).

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:

network:
  allowed:
    - defaults
    - "awmgmcpg"

See Network Configuration for more information.

Generated by CI Outer-Loop Failure Scanner · 675.2 AIC · ⌖ 17.8 AIC · ⊞ 18.3K · ◷

Report

Build	Repository	Test	Pull Request
1537347	dotnet/runtime	GC/Regressions/v2.0-rtm/544701/544701/544701.dll	#131727
1536986	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1536541	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1536350	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1536154	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1535811	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1535331	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1534392	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1533803	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
3	9	9

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1532833
Error message validated: [Running test: GC.Regressions.v2.0-rtm.544701.544701.544701.dll Unexpected Exception when allocating 41938869 bytes. Failed test: GC.Regressions.v2.0-rtm.544701.544701.544701.dll]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 8/3/2026 9:27:27 PM UTC

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1532833
Error message validated: [Running test: GC.Regressions.v2.0-rtm.*544701.dll Unexpected Exception when allocating 41938869 bytes. Failed test: GC.Regressions.v2.0-rtm.*544701.dll]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 8/3/2026 9:28:43 PM UTC

Report

Build	Repository	Test	Pull Request
1543362	dotnet/runtime	GC/Regressions/v2.0-rtm/544701/544701/544701.dll
1539701	dotnet/runtime	GC/Regressions/v2.0-rtm/544701/544701/544701.dll	#131411
1542734	dotnet/runtime	GC/Regressions/v2.0-rtm/544701/544701/544701.dll	#131907
1542248	dotnet/runtime	GC/Regressions/v2.0-rtm/544701/544701/544701.dll
1541786	dotnet/runtime	GC/Regressions/v2.0-rtm/544701/544701/544701.dll	#131907
1541654	dotnet/runtime	GC\Regressions\v2.0-rtm\544701\544701\544701.dll
1540632	dotnet/runtime	GC/Regressions/v2.0-rtm/544701/544701/544701.dll
1539929	dotnet/runtime	GC\Regressions\v2.0-rtm\544701\544701\544701.dll
1538838	dotnet/runtime	GC/Regressions/v2.0-rtm/544701/544701/544701.dll
1538148	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1537347	dotnet/runtime	GC\Regressions\v2.0-rtm\544701\544701\544701.dll	#131727
1536986	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1536541	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1536350	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1536154	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1535811	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1535331	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1534392	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1533803	dotnet/runtime	GC/API/GC/GetTotalAllocatedBytesServerGC/GetTotalAllocatedBytesServerGC.cmd
1532833	dotnet/runtime	GC/Regressions/v2.0-beta2/445488/445488/445488.dll

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
4	18	20

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1532833
Error message validated: [Running test: GC.Regressions.v2.0-rtm.544701.544701.544701.dll Unexpected Exception when allocating 41938869 bytes. Failed test: GC.Regressions.v2.0-rtm.544701.544701.544701.dll]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 8/3/2026 9:27:27 PM UTC

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1532833
Error message validated: [Running test: GC.Regressions.v2.0-rtm.*544701.dll Unexpected Exception when allocating 41938869 bytes. Failed test: GC.Regressions.v2.0-rtm.*544701.dll]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 8/3/2026 9:28:43 PM UTC

[dotnet-policy-service]

Tagging subscribers to this area: @anicka-net, @dotnet/gc
See info in area-owners.md if you want to be subscribed.

[github-actions]

Workflow artifact: ci-fix
Artifact kind: handoff
Linked KBE: #131629

Note

AI/Copilot-generated triage note.

This Known Build Error has no producible automated code change (reason: native GC/NativeAOT allocation defect — the failure is an unexpected exception during a large managed allocation in the NativeAOT GC, which is a runtime/GC product issue and must not be worked around in the regression test), so I could not open even a best-effort PR. Looping in owners so it can be fixed forward rather than muted.

Root cause (best analysis)

The GC regression test GC/Regressions/v2.0-rtm/544701 fails under NativeAOT on the runtime-nativeaot-outerloop pipeline (definition 265):

Running test: GC/Regressions/v2.0-rtm/544701/544701/544701.dll
Unexpected Exception when allocating 41938869 bytes.
Test Failed
Xunit.Sdk.EqualException: Assert.Equal() Failure: Values differ
Expected: 100
Actual:   -1

The test performs a ~40 MB managed allocation and expects it to succeed; instead the allocation throws an unexpected exception (the KBE notes System.OutOfMemoryException on the sibling 445488/460373 variants). The failure is inside the NativeAOT GC allocation path, not in the test logic — the test itself is a long-standing regression test that passes on CoreCLR. A test-side change here would only mask a real GC/NativeAOT allocation defect, so this is a hand-off rather than a fix or workaround PR.

Evidence

• Failing build: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1532833 (linux-x64 Checked NativeAOT_Pri1; signature confirmed still present in the cited build's timeline), reproduces in follow-up build 1533287.
• First build it occurred: source build 1532833 finished 2026-07-30T15:02Z (within scanned window; a post-close recurrence of the previously-filed, now-closed KBE [ci-scan] Test failure: GC/Regressions NativeAOT OutOfMemoryException (445488, 460373, 544701) #131529 — true origin may predate).
• Possible related PR: none identified with sufficient confidence.

Suggested reviewers / area contacts

• Area owners (area-GC-coreclr): @anicka-net, @dotnet/gc
• Area owners (area-NativeAOT-coreclr): @agocke, @dotnet/ilc-contrib

A fix would likely involve investigating why the NativeAOT GC rejects/faults a ~40 MB allocation on these outerloop legs (heap limit, region reservation, or large-object-heap handling under NativeAOT), rather than any change to the 544701 regression test.

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:

network:
  allowed:
    - defaults
    - "awmgmcpg"

See Network Configuration for more information.

Generated by CI Outer-Loop Failure Fixer · 390.9 AIC · ⌖ 15.3 AIC · ⊞ 17.1K · ◷

[JulieLeeMSFT]

@anicka-net, this test is failing every day. While we are waiting for a fix in .NET 12, should we disable the test?