macro
boot.janet on line 3825, column 3
(ev/with-deadline sec & body)
Create a fiber to execute `body`, schedule the event loop to cancel
the task (root fiber) associated with `body`'s fiber, and start
`body`'s fiber by resuming it.
The event loop will try to cancel the root fiber if `body`'s fiber
has not completed after at least `sec` seconds.
`sec` is a number that can have a fractional part.