The following layout test is flaky on Mac and iOS WK2 builds http/tests/resourceLoadStatistics/log-cross-site-load-with-link-decoration.html Probable cause: Test was added in https://trac.webkit.org/changeset/242603/webkit Appears to have been happening on Mac Release and Debug WK2 through the available history on the dashboard history, but it's also on High Sierra and iOS Simulator Debug recently. Can reproduce locally if I run the following, but only in full parallel, which could be causing a false positive. run-webkit-tests http/tests/resourceLoadStatistics/log-cross-site-load-with-link-decoration.html --iterations 500 -f Flakiness Dashboard: https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=http%2Ftests%2FresourceLoadStatistics%2Flog-cross-site-load-with-link-decoration.html