innobackupex fails to copy-back if dir performance_schema exists

[Rodrigo Gadea]

[rodrigo@macnorbur bktest]$ sudo innobackupex --copy-back /home/rodrigo/bktest/2011-05-23_23-01-18

InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Inc 2009-2011. All Rights Reserved.

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

IMPORTANT: Please check that the copy-back run completes successfully.
           At the end of a successful copy-back run innobackupex
           prints "completed OK!".

innobackupex: Starting to copy MyISAM tables, indexes,
innobackupex: .MRG, .TRG, .TRN, .ARM, .ARZ, .CSM, .CSV, .opt, and .frm files
innobackupex: in '/home/rodrigo/bktest/2011-05-23_23-01-18'
innobackupex: back to original data directory '/var/lib/mysql'
innobackupex: Copying directory '/home/rodrigo/bktest/2011-05-23_23-01-18/performance_schema'
mkdir: cannot create directory `/var/lib/mysql/performance_schema': File exists
innobackupex: Error: Failed to create directory '/var/lib/mysql/performance_schema' : No such file or directory at /usr/bin/innobackupex line 342.