[CI] Flaky: LinkAll Pasteboard_ImagesTest reports HasImages false

[dalexsoto]

Flaky test report

Stable signature: linkall-uipasteboard-hasimages-false
Test: LinkAll.LinkAllRegressionTest.Pasteboard_ImagesTest
Platform/job: iOS simulator, T: linker_ios
Classification: Genuinely flaky test
First observed: 2026-07-21 22:40:27 UTC
Latest observed: 2026-08-08 03:16:28 UTC

Failure

The test assigns an image to UIPasteboard.General.Images and immediately observes:

HasImages
Expected: True
But was:  False

Confirmed occurrences

PR / head	Azure run / attempt	Job / task	Outcome
#26146 / f447dd24780dc6c6e0274723f10648c932af6324	14720461, attempt 1	T: linker_ios	Failed with the exact assertion; rerun attempt 2 succeeded. The original task metadata is no longer retained.
#26356 / ccace789c2d7e5a48e1c00749d9244acb8c77528	14914057, attempt 1	T: linker_ios / Run tests	Failed; build was still running when recorded, so no retry had been requested.

Recurrence: 2 confirmed occurrences across 2 distinct PRs.

Investigation

• The current TestSummary reports one failed and 30 passed linker configurations; the HtmlReport identifies this as the sole failed test in link all/iOS - simulator/Release.
• The earlier occurrence cleared on the same-head Azure rerun, while the PR changes were unrelated to pasteboard behavior.
• tests/monotouch-test/UIKit/PasteboardTest.cs already documents random clipboard/image behavior and ignores its equivalent image test even after retries.
• Closed issue [xcode11] link all/iOS: [FAIL] LinkAllRegressionTest.Pasteboard_ImagesTest : a - length  #6254 was inspected but tracks a different Images.Length == 1 assertion and an Xcode 11 workaround, not this HasImages == false signature.

Impact and workaround

This blocks the iOS linker job and can fail the simulator pipeline. The observed workaround is to rerun the failed job after the pipeline is terminal and normal head, mergeability, retry-budget, and duplicate-attempt gates pass.

Artifacts and historical Azure logs are retention-limited; the current TestSummary and HtmlReport were available when this issue was created.

[dalexsoto]

Retry outcome for linkall-uipasteboard-hasimages-false:

• PR [net11.0] Update dependencies from dotnet/dotnet #26356, head ccace789c2d7e5a48e1c00749d9244acb8c77528: Azure run 14914057, attempt 2, T: linker_ios succeeded at 2026-08-08 05:39:13 UTC. The exact Pasteboard_ImagesTest / HasImages: Expected True, but was False failure did not reproduce.
• The overall retry run finished failed only because unrelated source-related failures reproduced in dotnettests_ios, dotnettests_maccatalyst, dotnettests_macos, and dotnettests_tvos: deterministic app-size baseline drift and Hot Reload System.BadImageFormatException: Bad IL range.
• Classification remains genuinely flaky. Recurrence remains 2 distinct PRs / 2 confirmed failure occurrences; both occurrences cleared on attempt 2. Retry accounting is 3/25 for the PR lifetime and 1/10 for this head.
• Additional info to collect: none requested in the issue body.