backup option "--galera-info" FAILs creation of 'xtrabackup_*' files -> ERROR: "Failed to get master wsrep state from SHOW STATUS"

	mariadb --version

		mariadb  Ver 15.1 Distrib 10.4.7-MariaDB, for Linux (x86_64) using readline 5.1

	mariabackup --version

		mariabackup based on MariaDB server 10.4.7-MariaDB Linux (x86_64)

	lsb_release -rd

		Description:    openSUSE Leap 15.1

		Release:        15.1

	mariabackup \

	  --user="testuser" \

	  --password="testpass" \

	 --backup \

	 --rsync \

	 --target-dir="/tmp/test" \

	cd /tmp/test

	find . | grep xtra

		xtrabackup_checkpoints

		xtrabackup_binlog_info

		xtrabackup_info

	mariabackup \

	  --user="testuser" \

	  --password="testpass" \

	 --backup \

	 --rsync \

+	 --galera-info \

	 --target-dir="/tmp/test" \

	cd /tmp/test

	find . | grep xtra

		(empty)

	cat bkup.log

		[00] 2019-07-27 09:25:02 Connecting to MySQL server host: localhost, user: testuser, password: set, port: 3306, socket: /run/mariadb/mariadb.sock

		[00] 2019-07-27 09:25:02 Using server version 10.4.7-MariaDB-log

		/usr/local/mariadb/bin/mariabackup based on MariaDB server 10.4.7-MariaDB Linux (x86_64)

		[00] 2019-07-27 09:25:02 uses posix_fadvise().

		[00] 2019-07-27 09:25:02 cd to /data/db/mariadb/

		[00] 2019-07-27 09:25:02 Loading encryption plugin

		[00] 2019-07-27 09:25:02         Encryption plugin parameter :  '--file_key_management_encryption_algorithm=aes_ctr'

		[00] 2019-07-27 09:25:02         Encryption plugin parameter :  '--file_key_management_filekey=FILE:/etc/mariadb/enc/pass.txt'

		[00] 2019-07-27 09:25:02         Encryption plugin parameter :  '--file_key_management_filename=/etc/mariadb/enc/keys.enc'

		[00] 2019-07-27 09:25:02 open files limit requested 0, set to 65000

		[00] 2019-07-27 09:25:02 mariabackup: using the following InnoDB configuration:

		[00] 2019-07-27 09:25:02 innodb_data_home_dir =

		[00] 2019-07-27 09:25:02 innodb_data_file_path = ibdata1:12M:autoextend

		[00] 2019-07-27 09:25:02 innodb_log_group_home_dir = ./

		[00] 2019-07-27 09:25:02 InnoDB: Using Linux native AIO

		2019-07-27  9:25:02 0 [Note] InnoDB: Number of pools: 1

		[00] 2019-07-27 09:25:02 mariabackup: Generating a list of tablespaces

		2019-07-27  9:25:02 0 [Warning] InnoDB: Allocated tablespace ID 2 for mysql/innodb_index_stats, old maximum was 0

		[00] 2019-07-27 09:25:02 >> log scanned up to (143408)

		[01] 2019-07-27 09:25:02 Copying ibdata1 to /tmp/test/ibdata1

		[01] 2019-07-27 09:25:02         ...done

		[01] 2019-07-27 09:25:03 Copying ./mysql/innodb_index_stats.ibd to /tmp/test/mysql/innodb_index_stats.ibd

		[01] 2019-07-27 09:25:03         ...done

		[01] 2019-07-27 09:25:03 Copying ./mysql/innodb_table_stats.ibd to /tmp/test/mysql/innodb_table_stats.ibd

		[01] 2019-07-27 09:25:03         ...done

		[01] 2019-07-27 09:25:03 Copying ./mysql/transaction_registry.ibd to /tmp/test/mysql/transaction_registry.ibd

		[01] 2019-07-27 09:25:03         ...done

		[01] 2019-07-27 09:25:03 Copying ./mysql/gtid_slave_pos.ibd to /tmp/test/mysql/gtid_slave_pos.ibd

		[01] 2019-07-27 09:25:03         ...done

		[00] 2019-07-27 09:25:03 Starting prep copy of non-InnoDB tables and files

		[00] 2019-07-27 09:25:03 >> log scanned up to (143408)

		[00] 2019-07-27 09:25:03 Starting rsync as: rsync -t . --files-from=/run/mariadbtmp/xtrabackup_rsyncfiles_pass1 /tmp/test/

		[00] 2019-07-27 09:25:04 rsync finished successfully.

		[00] 2019-07-27 09:25:04 Finished a prep copy of non-InnoDB tables and files

		[00] 2019-07-27 09:25:04 Acquiring BACKUP LOCKS...

		[00] 2019-07-27 09:25:04 Starting to backup non-InnoDB tables and files

		[00] 2019-07-27 09:25:04 Starting rsync as: rsync -t . --files-from=/run/mariadbtmp/xtrabackup_rsyncfiles_pass2 /tmp/test/

		[00] 2019-07-27 09:25:04 rsync finished successfully.

		[00] 2019-07-27 09:25:04 Finished backing up non-InnoDB tables and files

		[01] 2019-07-27 09:25:04 Copying aria_log.00000001 to /tmp/test/aria_log.00000001

		[01] 2019-07-27 09:25:04         ...done

		[01] 2019-07-27 09:25:04 Copying aria_log_control to /tmp/test/aria_log_control

		[01] 2019-07-27 09:25:04         ...done

		[00] 2019-07-27 09:25:04 Waiting for log copy thread to read lsn 143408

		[00] 2019-07-27 09:25:04 >> log scanned up to (143408)

		[00] 2019-07-27 09:25:04 Failed to get master wsrep state from SHOW STATUS.

		mariabackup: Stopping log copying thread.[00] 2019-07-27 09:25:04 >> log scanned up to (143408)