xtrabackup_55: Error writing file 'UNOPENED' (Errcode: 32)

SmartOS and percona-cluster-5.5.31nb3

Error in /var/log/mysql/error.log

WSREP_SST: [INFO] Streaming the backup to joiner at 192.168.0.5 4444 (20131210 11:16:26.461)
WSREP_SST: [ERROR] innobackupex finished with error: 3.  Check /var/mysql//innobackup.backup.log (20131210 11:16:27.891)
WSREP_SST: [ERROR] Cleanup after exit with status:22 (20131210 11:16:27.912)
131210 11:16:27 [ERROR] WSREP: Failed to read from: wsrep_sst_xtrabackup --role 'donor' --address '192.168.0.5:4444/xtrabackup_sst' --auth 'sst:secret' --socket '/tmp/mysql.sock' --datadir '/var/mysql/' --defaults-file '/opt/local/etc/my.cnf' --gtid '6ceed930-6185-11e3-ae0d-8e7504b63f54:2'
131210 11:16:27 [ERROR] WSREP: Process completed with error: wsrep_sst_xtrabackup --role 'donor' --address '192.168.0.5:4444/xtrabackup_sst' --auth 'sst:secret' --socket '/tmp/mysql.sock' --datadir '/var/mysql/' --defaults-file '/opt/local/etc/my.cnf' --gtid '6ceed930-6185-11e3-ae0d-8e7504b63f54:2': 22 (Invalid argument)
131210 11:16:27 [Warning] WSREP: 0 (node1): State transfer to 1 (node2) failed: -1 (Not owner)
 

And in /var/mysql//innobackup.backup.log you see

xtrabackup_55: Error writing file 'UNOPENED' (Errcode: 32) 

I've removed

 [sst]
streamfmt = xbstream

from /opt/local/etc/my.cnf