[CI] iOS 27 monotouch-test stalls in NSUrlSession redirect tests with simulator daemon crash loops

[dalexsoto]

Failure signature

monotouch-test starts executing MonoTests.System.Net.Http.MessageHandlerTest on the iOS 27 simulator, reaches the NSUrlSession credential/cross-origin redirect tests, then stops producing test output until xharness' 15-minute timeout. The same runs collect repeated intelligencetasksd crash reports and a SpringBoard crash report.

Representative last test activity:

MonoTests.System.Net.Http.MessageHandlerTest.NSUrlSessionHandlerCredentialsCrossOriginRedirectTarget

or immediately after:

[PASS] NSUrlSessionHandlerOriginCredentialCacheNotSentToCrossOriginRedirectTarget

Confirmed occurrences

PR / head	Build and job	Timed-out variations
#26200 / 966f7cc95666adf0926c09964990868e5f161864	14718622 - monotouch_ios	Release (trimmable static registrar, NativeAOT) and Release (managed static registrar, all optimizations)
#26208 / 34b9f4d4972752561d6769b7f1ef0fbe276e049c	14718968 - monotouch_ios	Release (NativeAOT, .NET 11 defaults)

First observed: 2026-07-21 15:25 UTC. Latest observed: 2026-07-21 17:36 UTC. Recurrence: 3 variations across 2 distinct monitored PRs.

Diagnosis and impact

This is classified as a genuinely flaky iOS 27 simulator/NSUrlSession failure:

• The affected PRs modify unrelated framework bindings.
• Other monotouch-test variations in the same jobs pass.
• The failure is a silent stall rather than an assertion or product build error.
• Repeated simulator-daemon crashes accompany each timeout.

The failure blocks the complete simulator-test stage. The current workaround is to rerun failed jobs after the build is terminal and retry/merge gates permit it. Test reports and crash artifacts have limited retention.

[dalexsoto]

New affected PR: #26158 @ eca5c5b88045ef1ed57d5e572cbea1f4fd2a9cde, build 14719100, job monotouch_ios. The Release (compat inline dlfcn) variation stalled in MessageHandlerTest.NSUrlSessionHandlerCredentialsCrossOriginRedirectTarget, timed out after 15 minutes, and collected repeated intelligencetasksd plus SpringBoard crash reports.

The signature now affects 4 variations across 3 monitored PRs. Build 14719100 remains in progress, so no retry has been requested.

[dalexsoto]

New affected PR: #26180 @ 897e85a4b8e8e206c57ea59a7b0c3088abf18e15, build 14718322, simulator_tests attempt 2 job monotouch_ios. The trimmable-static-registrar NativeAOT variation timed out after 15 minutes with repeated intelligencetasksd and SpringBoard crashes.

The signature now affects 5 variations across 4 monitored PRs. Attempt 2 finished failed; simulator_tests attempt 3 was accepted at 21:20 UTC.

[dalexsoto]

Retry update for PR #26180: build 14718322 simulator_tests attempt 3 did not reach the NSUrlSession tests. The retried monotouch_ios job failed while generating BosStorageMirror SAS tokens because Azure DevOps returned TF10216; that outage is tracked by #26224. The stage attempt remains active, so no further retry was submitted.

[dalexsoto]

PR #26180 retry update: simulator_tests attempt 3 failed before tests on the Azure TF10216 outage tracked by #26224. Build 14718322 is terminal, and attempt 4 was accepted at 00:24 UTC to rerun monotouch_ios. Reconciled budget: 5 lifetime / 3 current-head retries.

[dalexsoto]

Retry outcome: PR #26200 build 14718622 simulator_tests attempt 2 completed with monotouch_ios succeeding. The overall attempt failed on a separate Apple runtime-download timeout tracked by #26223.

[dalexsoto]

Final retry outcome: merged PR #26158 build 14719100 simulator_tests attempt 2 completed successfully at 01:57 UTC. Monotouch_ios passed, the overall build succeeded, and the PR merged at 02:01 UTC.

[dalexsoto]

New monitored recurrence on PR #26208 @ 34b9f4d4972752561d6769b7f1ef0fbe276e049c, build 14718968, simulator_tests attempt 2 job monotouch_ios. Release (all optimizations) stalled in MessageHandlerTest NSUrlSession credential/redirect coverage, with repeated intelligencetasksd crash reports, until the 15-minute timeout.

The durable monitoring ledger now has this signature on 4 distinct PRs. Attempt 3 was accepted at 02:22 UTC; reconciled budget is 3 lifetime/current-head retries.

[dalexsoto]

Final retry outcome: merged PR #26180 build 14718322 simulator_tests attempt 4 completed successfully at 02:33 UTC. Monotouch_ios passed, the overall build succeeded, and the PR merged at 02:37 UTC.

[dalexsoto]

New recurrence on PR #26283 @ 11a1165bea, build 14776674, attempt 1 job monotouch_ios. The Release (trimmable static registrar, NativeAOT) variation passed NSUrlSessionHandlerOriginCredentialCacheNotSentToCrossOriginRedirectTarget, then stalled in the same parameterized cross-origin credential coverage until the 15-minute timeout. The app built, launched, connected, and began tests; no Photos tests were involved. Simulator reports again included SpringBoard and background-service crashes. Failed-job retry attempt 2 was accepted at 18:00 UTC and is now running.

[dalexsoto]

Retry outcome for PR #26283: build 14776674 simulator_tests attempt 2 completed successfully at 20:01 UTC. monotouch_ios passed and the full PR check matrix is green; no code change was needed.