--no-timestamp gives a "failed to create backup directory" error if the root backup dir already exists

[root@node3 ~]# mkdir backup
[root@node3 ~]# innobackupex --galera-info --no-timestamp backup

InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Ireland Ltd 2009-2012. All Rights Reserved.

This software is published under
the GNU GENERAL PUBLIC LICENSE Version 2, June 1991.

130401 14:51:43 innobackupex: Starting mysql with options: --unbuffered --
130401 14:51:43 innobackupex: Connected to database with mysql child process (pid=13165)
130401 14:51:49 innobackupex: Connection to database server closed
IMPORTANT: Please check that the backup run completes successfully.
           At the end of a successful backup run innobackupex
           prints "completed OK!".

innobackupex: Using mysql Ver 14.14 Distrib 5.5.29, for Linux (i686) using readline 5.1
innobackupex: Using mysql server version Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

innobackupex: Error: Failed to create backup directory backup: File exists at /usr/bin/innobackupex line 381.

[root@node3 ~]# rmdir backup
[root@node3 ~]# innobackupex --galera-info --no-timestamp backup

InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Ireland Ltd 2009-2012. All Rights Reserved.

This software is published under
the GNU GENERAL PUBLIC LICENSE Version 2, June 1991.

130401 14:53:38 innobackupex: Starting mysql with options: --unbuffered --
130401 14:53:38 innobackupex: Connected to database with mysql child process (pid=13252)
130401 14:53:44 innobackupex: Connection to database server closed
IMPORTANT: Please check that the backup run completes successfully.
           At the end of a successful backup run innobackupex
           prints "completed OK!".

innobackupex: Using mysql Ver 14.14 Distrib 5.5.29, for Linux (i686) using readline 5.1
innobackupex: Using mysql server version Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

innobackupex: Created backup directory /root/backup
130401 14:53:44 innobackupex: Starting mysql with options: --unbuffered --
130401 14:53:44 innobackupex: Connected to database with mysql child process (pid=13279)
130401 14:53:46 innobackupex: Connection to database server closed

130401 14:53:46 innobackupex: Starting ibbackup with command: xtrabackup_55 --defaults-group="mysqld" --backup --suspend-at-end --target-dir=/root/backup --tmpdir=/tmp
innobackupex: Waiting for ibbackup (pid=13287) to suspend
innobackupex: Suspend file '/root/backup/xtrabackup_suspended'

xtrabackup_55 version 2.0.6 for Percona Server 5.5.16 Linux (i686) (revision id: 521)
xtrabackup: uses posix_fadvise().
xtrabackup: cd to /var/lib/mysql
xtrabackup: Target instance is assumed as followings.
xtrabackup: innodb_data_home_dir = ./
xtrabackup: innodb_data_file_path = ibdata1:10M:autoextend
xtrabackup: innodb_log_group_home_dir = ./
xtrabackup: innodb_log_files_in_group = 2
xtrabackup: innodb_log_file_size = 67108864
>> log scanned up to (79201709)
[01] Copying ./ibdata1 to /root/backup/ibdata1
[01] ...done

130401 14:53:49 innobackupex: Continuing after ibbackup has suspended
130401 14:53:49 innobackupex: Starting mysql with options: --unbuffered --
130401 14:53:49 innobackupex: Connected to database with mysql child process (pid=13301)
130401 14:53:51 innobackupex: Starting to lock all tables...
>> log scanned up to (79201709)
>> log scanned up to (79201709)
>> log scanned up to (79201709)
130401 14:54:05 innobackupex: All tables locked and flushed to disk

130401 14:54:05 innobackupex: Starting to backup non-InnoDB tables and files
innobackupex: in subdirectories of '/var/lib/mysql'
innobackupex: Backing up file '/var/lib/mysql/test/sbtest1.frm'
innobackupex: Backing up files '/var/lib/mysql/performance_schema/*.{frm,MYD,MYI,MAD,MAI,MRG,TRG,TRN,ARM,ARZ,CSM,CSV,opt,par}' (18 files)
innobackupex: Backing up files '/var/lib/mysql/mysql/*.{frm,MYD,MYI,MAD,MAI,MRG,TRG,TRN,ARM,ARZ,CSM,CSV,opt,par}' (72 files)
130401 14:54:06 innobackupex: Finished backing up non-InnoDB tables and files

130401 14:54:06 innobackupex: Waiting for log copying to finish

xtrabackup: The latest check point (for incremental): '79201555'
xtrabackup: Stopping log copying thread.
.>> log scanned up to (79201709)

xtrabackup: Transaction log of lsn (79201555) to (79201709) was copied.
130401 14:54:09 innobackupex: All tables unlocked
130401 14:54:09 innobackupex: Connection to database server closed

innobackupex: Backup created in directory '/root/backup'
innobackupex: MySQL binlog position: filename '', position
130401 14:54:09 innobackupex: completed OK!