Why backup database by Barman can't reach end(pending)?
The reason was I did recovery after the first backup operation. Then Barman set a string #BARMAN# ahead archive_command = 'barman-wal-archive backup pg %p' command into the postgresql.conf file!

So it can't call that command when do the second backup.

Remove the string, it works.

The design to aim to don't allow user to use archive_command again after recovery?