I guess you're right, I've moved it further down. There is in fact a message about the xlog location (unless you switch off wal entirely), but having another one right before that mentioning the completed checkpoint sounds ok to me.
1) I don't think this should be verbose output. Having a program sit there "doing nothing" for no apparent reason is just horrible UI design.
That would include much of Unix then.. For example if I run "cp" on a large file it sits around "doing nothing". Same if I do "tar". No?
2) I think it'd be useful to have a way to get the status of a running checkpoint. The checkpointer already has that info, and I think it might even be in shared memory already. If there was a function that reported checkpoint status pg_basebackup could poll that to provide users with live status. That should be a separate patch though.
I agree that this would definitely be useful. But it might be something that's better exposed as a server-side view?
(and if pg_basebackup could poll it it would probably still not be included by default -- only if -P was given).