DeathTest doesn't catch all exceptions and can let children that were supposed to die think that they're parents who need to run tests, thus causing recursion. Fix DeathTest such that the children can't escape their dying context.

util_test tests that massert dies, but massert doesn't die and instead just throws, resuling in the above error. Just remove the massert tests.

Hopefully this doesn't uncover some other hitherto unseen failure.