We're stuck. Peter wants to make Throwables cloneable, I want to reverse the order of throwables and add the past Throwable as a suppressed exception to the exception of a dependent action, and Doug wants the current webrev behavior of adding the dependent action as a suppressed exception of the source.
I'm willing to accept the small incompatibility of throwing a different exception when everything fails; the existing spec doesn't promise what happens in this case.
