Comment 5 for bug 822697

duplicity 0.7.07.1 (April 19, 2016)
Args: /usr/bin/duplicity full --encrypt-key xxxx --rsync-options="-oIdentityFile=/home/$user/.ssh/xxxxxxx.ke" --progress --volsize 1024 --exclude=/proc --exclude=/sys --exclude=/dev --exclude=/proc --exclude=/sys --exclude=/mnt --exclude=/media --exclude=/tmp --exclude=/var/spool --exclude=/var/cache --exclude=/var/tmp / rsync://$user@$host//data/backup/$client -v info
Linux $client 2.6.32-573.18.1.el6.x86_64 #1 SMP Tue Feb 9 22:46:17 UTC 2016 x86_64 x86_64
/usr/bin/python2 2.6.6 (r266:84292, Jul 23 2015, 15:22:56)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-11)]

Reading results of 'rsync -e 'ssh -oBatchMode=yes' -oIdentityFile=/root/.ssh/xxxxxxx.key $user@$host:/data/backup/snozzle/'
Attempt 1 failed. BackendException: Error running 'rsync -e 'ssh -oBatchMode=yes' -oIdentityFile=/root/.ssh/duplicity_snozzle.key $user@$host:/data/backup/snozzle/': returned 14,

The Issue is:
--rsync-options="-oIdentityFile=/home/$user/.ssh/xxxxxxx.key"

the built rsync options are:
'rsync -e 'ssh -oBatchMode=yes' -oIdentityFile=/root/.ssh/xxxxxxx.key $user@$host//data/backup/$client'

He're the -oIdentityFile= is not included to the rsync -e '..' command, so it will not be interpreted the correct way by rsync. If you use a -i lalala.key the issue persits.