Use Vector for EventHandler #4028
ArrayList::add is not thread safe. I ran into cases where async tests
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But I also recently discovered #4010 in the context of Scalacheck forked tests, which has the same symptom you're reporting: a single test failure doesn't fail the entire suite. That wasn't a race condition, but a problem of losing data by clobberring a binding in a map of results, when the test framework created many nested
@eatkins How sure are you that this change (alone) fixes the problem you saw?