A negative --retry skipped the compile loop, leaving a nil error inside
exitError that panicked when printed.
- reject a negative or oversized --retry and a non-positive --timeout as
usage errors (exit 3)
- print an exit code when exitError carries no inner error
- cap the backoff shift so a large --retry cannot overflow
- cancel the sibling compile on the first failure, and do not report that
cancellation as the cause
- report a context cancellation during the retry backoff instead of the
stale compile error
unkin-agent
6e4ee54203