Comment 12 for bug 1266763

@kurt:
More attention will be required for the lockfile housekeeping. A simple test fails because of a lingering lockfile. Here is an example :

ubuntu@PreciseS:~$ duplicity --exclude /backup --exclude /proc / file:///backup
Local and Remote metadata are synchronized, no sync needed.
Last full backup date: none
GnuPG passphrase:
Retype passphrase to confirm:
No signatures found, switching to full backup.
Error accessing possibly locked file /boot/System.map-3.5.0-23-generic
....
Error accessing possibly locked file /home/ubuntu/.viminfo
[Errno 13] Permission denied: '/backup/duplicity-full.20140116T140006Z.vol1.difftar.gpg'
ubuntu@PreciseS:~$ duplicity --exclude /backup --exclude /proc / file:///backup
Local and Remote metadata are synchronized, no sync needed.
Last full backup left a partial set, restarting.
Last full backup date: Thu Jan 16 15:00:06 2014
GnuPG passphrase:
Retype passphrase to confirm:
RESTART: The first volume failed to upload before termination.
         Restart is impossible...starting backup from beginning.
Another instance is already running with this archive directory