imported/w3c/web-platform-tests/IndexedDB/interfaces.worker.html is a flaky timeout on macOS WK1 release testers according to the flakiness dashboard: https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=imported%2Fw3c%2Fweb-platform-tests%2FIndexedDB%2Finterfaces.worker.html The test usually runs ing 1-2 seconds on release builds but will occasionally timeout with times between 35 seconds and 50 seconds https://build.webkit.org/results/Apple%20Sierra%20Release%20WK1%20(Tests)/r223253%20(5265)/results.html https://build.webkit.org/builders/Apple%20Sierra%20Release%20WK1%20(Tests)/builds/5265