Helix Android queues repeatedly assign unhealthy devices to MAUI R2R work items #17483

Summary

The dotnet/android public PR pipeline is seeing frequent infrastructure failures in MAUI ReadyToRun smoke tests submitted to the Helix Android device queues.

The submissions succeed and the work items are scheduled, but device setup fails before the APK is launched. This is affecting unrelated non-fork PRs and same-commit reruns pass when assigned to healthy devices.

Full dotnet/android tracking issue: dotnet/android#12658

Impact

Sample window: the latest 100 completed dotnet-android builds from 2026-08-31 through 2026-09-03.

Of 92 builds containing the MAUI R2R Helix task, 72 passed, 19 failed, and 1 was skipped. Excluding eight separately understood fork-token failures, 11 direct-PR builds contained 12 failed Helix work items:

• 8 Android package-manager/UID exhaustion failures
• 3 ADB authorization timeouts
• 1 work item with no Android device detected

All 12 failed before APK launch and therefore do not demonstrate a MAUI or ReadyToRun product regression.

Affected work items

Failure signatures

The ARM32 failures are concentrated on one host/device pair:

Helix machine: DNCENGWIN-141
Android device: 27091JEGR21946
Queue: windows.11.amd64.android-armel.open

List of devices attached
27091JEGR21946         unauthorized transport_id:1
adb.exe wait-for-device
END OF WORK ITEM LOG: Command timed out, and was killed

The ARM64 package-manager failures occur across seven Helix machines and six Android devices:

adb.exe uninstall com.xamarin.mauir2r.arm64.fullr2r
Failure [DELETE_FAILED_INTERNAL_ERROR]

adb.exe install -r MauiR2R-android-arm64-fullr2r-Signed.apk
Failure [INSTALL_FAILED_INSUFFICIENT_STORAGE: Scanning Failed.: Package ... could not be assigned a valid UID]

One work item on DNCENGWIN-034 had no device listed at all before adb wait-for-device timed out.

Same-commit rerun evidence

• [typemap] Diagnose unsupported export signatures android#12597: failed in build 1578760; MAUI task passed in 1579125
• [r8-obfuscation] Add PE metadata rebuild substrate android#12629: failed in build 1577702; passed in 1578074
• [ci] Fix MAUI R2R Helix submissions for fork PRs android#12641: failed in build 1578755; MAUI task passed in 1579094 and 1579507

Action requested for Engineering Services / Helix

• Quarantine or re-authorize Android device 27091JEGR21946 attached to DNCENGWIN-141.
• Investigate and clean/reprovision the affected ARM64 devices' package-manager state.
• Investigate why DNCENGWIN-034 accepted work while no Android device was visible.
• Consider queue health checks that reject hosts with missing/unauthorized devices or exhausted Android package-manager state before assigning work.