217001 2020-09-25 16:41:51 -0700 fast/scrolling/latching/latched-scroll-into-nonfast-region.html is a flaky failure 2020-10-17 18:40:25 -0700 1 1 1 Unclassified WebKit Scrolling WebKit Nightly Build Unspecified Unspecified NEW InRadar P2 Normal --- 1 rackler webkit-unassigned ap simon.fraser webkit-bot-watchers-bugzilla webkit-bug-importer oldest_to_newest 1692105 0 rackler 2020-09-25 16:41:51 -0700 Description: fast/scrolling/latching/latched-scroll-into-nonfast-region.html The first failure that I see this on the dashboard was 09/03/20 at r266538 on Catalina debug wk2. It has had a frequency of approximately every 4 days, but on 09/16/20 increased in frequency to daily occurrences. I can reproduce this on r266932, but unable to reproduce on r266931. Commit r266932 has to do with MediaToolboxSoftLink.cpp and MediaToolboxSoftLink.h, which could have introduced the flakiness. The change was introduced here https://trac.webkit.org/changeset/266932/webkit. REPRODUCTION STEPS Command: run-webkit-tests --iterations 2000 --exit-after-n-failures 1 --exit-after-n-crashes-or-timeouts 1 --debug-rwt-logging --no-retry --force --no-build -f fast/scrolling/latching/latched-scroll-into-nonfast-region.html Result: Regressions: Unexpected text-only failures (1) fast/scrolling/latching/latched-scroll-into-nonfast-region.html [ Failure ] History: https://results.webkit.org/?suite=layout-tests&test=fast%2Fscrolling%2Flatching%2Flatched-scroll-into-nonfast-region.html&limit=50000&version_name=Catalina&flavor=wk2 Diff Log: --- /Volumes/Data/slave/catalina-release-tests-wk2/build/layout-test-results/fast/scrolling/latching/latched-scroll-into-nonfast-region-expected.txt +++ /Volumes/Data/slave/catalina-release-tests-wk2/build/layout-test-results/fast/scrolling/latching/latched-scroll-into-nonfast-region-actual.txt @@ -4,7 +4,7 @@ Scrolling the main frame with latching -PASS wheelEventHandlerCount is 0 +FAIL wheelEventHandlerCount should be 0. Was 3. PASS successfullyParsed is true TEST COMPLETE 1692107 1 webkit-bug-importer 2020-09-25 16:42:34 -0700 <rdar://problem/69600982> 1698581 2 rackler 2020-10-16 07:18:48 -0700 This issue is also affecting Mojave. I have marked this test as failing also on Mojave while this issue is investigated. https://trac.webkit.org/changeset/268588/webkit 1699043 3 ap 2020-10-17 18:40:25 -0700 Looking at test history (both webkit.org and internal), I think that this was just landed flaky. Frequency mysteriously changes over time, but some bots saw multiple failures a day from the start.