[CI] Secure-file download fails with TF15004 expired request signature

[dalexsoto]

Failure signature

The Azure DevOps DownloadSecureFile@1 pre-job fails before checkout or test execution while downloading macios-certificates-and-provisioning-profiles.zip:

Error: Failed to download secure file. HTTP 500: Internal Server Error.
TF15004: The download request signature has expired.

Stable signature: tf15004-expired-secure-file-download-request-signature

Confirmed occurrences

PR / head	Azure run, attempt, job, and task	Worker / time (UTC)
#26523 / 009d29239569f16f51a09943cd8fbed39167fa2a	15178528 attempt 1 / monotouch_maccatalyst / secure-file pre-job	AcesShared 78, 2026-09-02 02:59:08
#26475 / 56d8ad2aa9785bf30a1522852177506bbd03240c	15194793 attempt 1 / dotnettests_multiple / secure-file pre-job	AcesShared 93, 2026-09-03 05:01:38

Total: 2 confirmed occurrences across 2 distinct monitored PRs.

First observed: 2026-09-02T02:59:08Z. Latest observed: 2026-09-03T05:01:38Z.

Classification and impact

CI infrastructure failure. The same Azure secure-file service error occurred on unrelated PRs, heads, jobs, and workers. The affected job cannot reach checkout, setup, build, or tests, so this is not evidence of a source or deterministic test regression.

Investigation performed

• Inspected authenticated Azure build timelines, task issue data, task logs, workers, attempts, and retained retry history for both occurrences.
• Verified the exact HTTP 500, TF15004, DownloadTicketValidationException, secure-file name, and expired-request-signature text.
• Searched all open and closed dotnet/macios issues separately by the exact code and message, secure-file name, and DownloadSecureFile component.
• [CI] Ventura Show Bot Info stalls until the 120-minute job timeout #26457 concerns a Ventura Show Bot Info hang, [CI] Expired Apple development certificates break signing-dependent PR tests #26382 concerns expired/missing signing credentials, and [META] Xcode 15.1 Support for .NET 8 and MAUI #19623 is an unrelated Xcode support discussion; none represents this download-ticket failure.

Azure logs and secure-file request metadata are retention-limited.

Retry status and workaround

• [release/10.0.1xx] [dotnet] Update Xcode 27.0 packages for .NET 10. #26523: a failed-jobs retry created simulator attempt 2; monotouch_maccatalyst passed on AcesShared 1 and this signature did not recur.
• [dotnet] Report a clear error for PublishReadyToRunComposite=false. Fixes #26456. #26475: the parent simulator build remains active, so retry is deferred until it is terminal and all other failures can be reconciled.

A failed-jobs retry can clear an isolated occurrence after the PR head, mergeability, active attempts, and retry budgets are refreshed. The infrastructure fix is to ensure the signed secure-file download ticket remains valid until the queued pre-job executes.

[dalexsoto]

Retry started for PR #26475, head 56d8ad2aa9785bf30a1522852177506bbd03240c:

• Build 15194793 completed attempt 1 failed with only T: dotnettests_multiple affected by the TF15004 secure-file ticket expiration.
• After refreshing the unchanged conflict-free head, terminal build, all observable runs and attempts, active equivalents, and retry counters, Azure accepted Rerun failed jobs for simulator_tests.
• Simulator stage attempt 2 is active; only T: dotnettests_multiple is pending.
• Retry usage is now 2 PR-lifetime / 1 current-head request.

The canonical count remains 2 confirmed occurrences across 2 PRs. The issue body has no Additional info to collect checklist. The terminal retry outcome will be reported when available.

[dalexsoto]

Successful retry outcome for PR #26475, head 56d8ad2aa9785bf30a1522852177506bbd03240c:

• Build 15194793, simulator attempt 2 reran only T: dotnettests_multiple on AcesShared 1.
• The job completed successfully at 2026-09-03 07:29:51 UTC, and the simulator stage completed successfully at 07:29:59 UTC.
• The TF15004 expired secure-file ticket failure did not recur. Parent result publication is still active.
• Retry usage remains 2 PR-lifetime / 1 current-head request.

The canonical count remains 2 confirmed occurrences across 2 PRs. The issue body has no Additional info to collect checklist.

[dalexsoto]

Final parent outcome for PR #26475, head 56d8ad2aa9785bf30a1522852177506bbd03240c:

• Build 15194793 completed partiallySucceeded at 2026-09-03 07:36:56 UTC after the successful simulator attempt 2.
• GitHub now reports 51 successful and 3 skipped checks with no failures.
• The TF15004 secure-file failure did not recur. Retry usage remains 2 PR-lifetime / 1 current-head request.

The canonical count remains 2 confirmed occurrences across 2 PRs. The issue body has no Additional info to collect checklist.