interferes with macroexpanders, perhaps they're not providing correct &env values during expansion
and more thorough tests for all the possible cases of throw+ args
formerly all non-Throwable objects appeared at the :object key in a new map. Improves interop between slingshot and ex-info/ex-data.
previously the cause was automatically captured within a try+ catch clause or nil otherwise. This could also be accomplished by allowing more flexibility in the throw+ arguments, but that's quite a bit more complicated to code.