pass -v to send as well if -n (don't actually send)
pass -v to send as well if -n (don't actually send)

passing -v to send causes progress statistics to be printed every
second, which we don't want, but it doesn't happen if we don't actually
send anything (and recv cannot print diagnostics if it doesn't receive a
stream, which is the -n case)

niksula/zfsbackup