162624 2016-09-27 10:08:18 -0700 Reproducible ASSERT(m_process->state() != WebProcessProxy::State::Launching) 2016-09-27 10:08:28 -0700 1 1 1 Unclassified WebKit WebKit2 Other Unspecified Unspecified NEW https://bugs.webkit.org/show_bug.cgi?id=136012 P2 Normal --- 1 ap webkit-unassigned andersca ddkilzer sam oldest_to_newest 1233926 0 ap 2016-09-27 10:08:18 -0700 This is pretty much a duplicate of bug 136012, just a different and more practical way to reproduce this assertion. Probably has user visible symptoms, as the state of UI process is quite broken once this happens. Running too many tests in parallel on a MacBook Pro reproduces this several times in a few seconds: run-webkit-tests -v --repeat 1000 -f --child-processes=50 svg/animations/begin-event-syncbase.svg