Raise build-stage timeout to 360m for CoreCLR outer-loop windows-arm64 cross-builds

[Copilot]

Fixes #127987.

Root cause

The windows-arm64 checked CoreCLR build is a cross-build (arm64 toolchain + every JIT variant + libraries) running on a Windows amd64 agent. It regularly exceeds AzDO's default 60-minute job timeout and is cancelled with:

The job running on agent NetCore-Public N ran longer than the maximum time of 60 minutes.

Confirmed against builds 1406635 (def 111, jitstress2-jitstressregs) and 1413322 (def 124, crossgen2) cited in #127987. linux-arm64 and osx-arm64 cross-builds finish under 60m, so only windows-arm64 cancels.

The steps: [] text the agentic CI scanner cited in #127987 is the normal per-decorator template-resolution output (system-pre-steps.yml, build-security-monitoring-pipeline-decorator, etc.) — it appears identically in every successful linux-arm64/osx-arm64 phase log and is not the failure signal.

Fix

Set timeoutInMinutes: 360 on the build-stage platform-matrix.yml invocation in:

• eng/pipelines/coreclr/templates/jit-outerloop-pipeline.yml (covers jitstress2-jitstressregs def 111, jitstress-isas-arm def 116, plus jitstress, jitstress-isas-x86/avx512, jitstress-random, jitstressregs[-x86], jit-cfg, jit-experimental, pgo, pgostress, ilasm)
• eng/pipelines/coreclr/gcstress0x3-gcstress0xc.yml (def 112)
• eng/pipelines/coreclr/r2r.yml (def 120)
• eng/pipelines/coreclr/crossgen2.yml (def 124)

360 minutes matches the existing build-stage timeout used by sibling libraries-jitstress*.yml / libraries-jitstress2-jitstressregs.yml / libraries-jitstress-random.yml.

Verification

Triggering the five affected pipelines on this PR via /azp run below.

[kotlarmilos]

/azp run runtime-coreclr jitstress2-jitstressregs
/azp run runtime-coreclr gcstress0x3-gcstress0xc
/azp run runtime-coreclr jitstress-isas-arm
/azp run runtime-coreclr r2r
/azp run runtime-coreclr crossgen2

[azure-pipelines]

No pipelines are associated with this pull request.

[Copilot]

Pull request overview

This PR updates CoreCLR pipeline templates to (1) select windows_arm64 Helix queues via centralized queue variables and (2) increase build-job timeouts to accommodate slower checked cross-build legs.

Changes:

• Switch windows_arm64 Helix queue selection in helix-queues-setup.yml from hardcoded queue strings to helix-platforms.yml variables.
• Increase timeoutInMinutes to 360 for checked build jobs in the JIT outerloop template and several CoreCLR pipelines.

Show a summary per file

File	Description
eng/pipelines/coreclr/templates/jit-outerloop-pipeline.yml	Raises checked build job timeout budget for outerloop build legs.
eng/pipelines/coreclr/templates/helix-queues-setup.yml	Binds windows_arm64 Helix queue selection to shared helix-platforms.yml variables.
eng/pipelines/coreclr/r2r.yml	Raises checked build job timeout budget for R2R pipeline.
eng/pipelines/coreclr/gcstress0x3-gcstress0xc.yml	Raises checked build job timeout budget for this gcstress pipeline.
eng/pipelines/coreclr/crossgen2.yml	Raises checked build job timeout budget for Crossgen2 pipeline.

Copilot's findings

Comments suppressed due to low confidence (1)

eng/pipelines/coreclr/templates/jit-outerloop-pipeline.yml:29

• The PR description focuses on Helix queue variable alignment, but this template change also increases build job timeouts to 360 minutes. Please update the PR description to mention this additional behavior change, or split the timeout increase into a separate PR to keep scope focused.

            # Windows-arm64 checked cross-build needs more than the default 60m AzDO job timeout.
            timeoutInMinutes: 360
            buildArgs: -s clr+libs -c $(_BuildConfig) -lc Release
            postBuildSteps:
              - template: /eng/pipelines/coreclr/templates/build-native-test-assets-step.yml
              - template: /eng/pipelines/common/upload-artifact-step.yml

• Files reviewed: 4/4 changed files
• Comments generated: 4