MariaBackup as SST method doesn't work

[w7089]

i've added
wsrep_sst_method = mariabackup
to [mysqld] section in my.cnf
as specified here
and getting errors in mariadb error.log while trying to configure cluster and starting mysqld

WSREP_SST: [ERROR] mariabackup not in path: /usr/sbin:/sbin:/usr//bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin (20180318 15:30:45.409)
2018-03-18 15:30:45 139657773836032 [ERROR] WSREP: Failed to read 'ready ' from: wsrep_sst_mariabackup --role 'joiner' --address '10.0.0.218' --datadir '/var/lib/mysql/' --parent '625' ''
Read: '(null)'
2018-03-18 15:30:45 139657773836032 [ERROR] WSREP: Process completed with error: wsrep_sst_mariabackup --role 'joiner' --address '10.0.0.218' --datadir '/var/lib/mysql/' --parent '625' '' : 2 (No such file or directory)
2018-03-18 15:30:45 139658158028544 [ERROR] WSREP: Failed to prepare for 'mariabackup' SST. Unrecoverable.
2018-03-18 15:30:45 139658158028544 [ERROR] Aborting

Using image with MariaDB 10.2.13.
Is it only possible to use rsync as SST method?

[grooverdan]

The maria-backup-10.2 package isn't installed in the container. Discussion per #141

For sst:

xtrabackup-v2 and probably mysqldump are available.

[wglambert]

Closing to redirect discussion to #111, as #141 was also redirected there.