Bug 240037 – [ iOS ] css3/background/background-repeat-space-content.html is a flaky image failure

• Status: NEW
• Component: New Bugs

[Karl Rackler]

Description:
css3/background/background-repeat-space-content.html

The first failure that I saw on the dashboard was 12/14/2021 at r287060, but this does not appear relevant to causing this issue.  This test seems to have been flaky since the start.

History:
https://results.webkit.org/?suite=layout-tests&test=css3%2Fbackground%2Fbackground-repeat-space-content.html&platform=ios&limit=50000

Image Diff:
https://build.webkit.org/results/Apple-iOS-15-Simulator-Release-WK2-Tests/250205@main%20(2446)/css3/background/background-repeat-space-content-diffs.html

[Radar WebKit Bug Importer]

<rdar://problem/92692179>

[Karl Rackler]

I have marked this test as a flaky image failure while this issue is investigated.

[Karl Rackler]

Pull request: https://github.com/WebKit/WebKit/pull/480

[EWS]

Test gardening commit r293739 (250227@main): <https://commits.webkit.org/250227@main>

Reviewed commits have been landed. Closing PR #480 and removing active labels.

[Simon Fraser (smfr)]

r293447 didn't fix this?

[Simon Fraser (smfr)]

For cases like this where the pixel differences are consistent, we should be using pixel tolerance to make them pass.

Example: r288449

[Karl Rackler]

REPRODUCTION STEPS
I can reproduce this on ToT (r293740).

Command: 
run-webkit-tests --root 293740 --ios-simulator --exit-after-n-failures 1 --exit-after-n-crashes-or-timeouts 1 --details --debug-rwt-logging --pixel-tests --tolerance 0.10 --iterations 2000 --no-retry css3/background/background-repeat-space-content.html

Result:  
Unexpected flakiness: image-only failures (1)
  css3/background/background-repeat-space-content.html [ ImageOnlyFailure Pass ]

[Alexey Proskuryakov]

How can this be flaky? We are just drawing the same circle.png in both actual and expected.