xtrabackup "failed to read metadata" Doing a staging run setting up a new xtrabackup restore script I'm running into a somewhat cryptic error I can't readily google a solution for.

I'm working with an incremental backup design.  During the initial copy back of the last full the an attempt to apply changes to the first incremental is failing with

xtrabackup: error: failed to read metadata from 
/var/tmp/mysql_backups/inc/day1/xtrabackup_checkpoints


The cited file is present and world readable.

It's contents are

backup_type = incremental
from_lsn = 12:4121088784
to_lsn = 12:4121089203
last_lsn = 12:4121089203


Thoughts on what to check from here?

Edit

I think I found my problem.  My testing server install was an ubuntu mysql default; not percona.  

https://bugs.launchpad.net/percona-xtrabackup/+bug/655584/comments/3
I think I found my problem. My testing server install was an ubuntu mysql default; not percona.

https://bugs.launchpad.net/percona-xtrabackup/+bug/655584/comments/3