Function retry 

pub fn retry(
    prev: Option<Duration>,
    image: &str,
    msg: &str,
    e: &Error,
) -> (Duration, String)

After a replica could not be created: how long to wait before the next attempt (prev was the last wait), and the service’s message. An image its registry does not have will not appear by itself (until someone pushes it), so that waits longest, and is said plainly instead of in incus’ words.