webanimations/marker-opacity-animation-no-effect.html Is a flaky image failure on iOS 15 and macOS wk2. History: https://results.webkit.org/?suite=layout-tests&test=webanimations%2Fmarker-opacity-animation-no-effect.html Result page: https://build.webkit.org/results/Apple-BigSur-Release-WK2-Tests/r284548%20(6019)/results.html
<rdar://problem/84477684>
Created attachment 441930 [details] Image diff
Marked test expectations https://trac.webkit.org/changeset/284565/webkit
I was able to reproduce the image failure locally using run-webkit-tests --force --iterations 500 --exit-after-n-failures 1 webanimations/marker-opacity-animation-no-effect.html The test passed with r284515 (though this revision failed on the testing bot) and failed with r284516. It looks like https://trac.webkit.org/changeset/284516/webkit caused the flaky image failure, but not sure since I think it is very strange that r284515 failed on the testing bot, but didn't fail locally (iterated 1000 times, but passed.)
Yes, it's very unlikely for r284516 to have caused this.
I think that it's just a coincidence that the test worked for a few build after having been added, and it's just a flaky test.
Ryan and Antoine confirmed this is resolved as of 5/20/2022.