Comment 2 for bug 1526557

after some experiment:
relative-paths work fine, but absolute-ones don't:

--------------------------------------------------------------------------
$ ls -R backup
backup/scene:
duplicity-full.20160101T045912Z.manifest.gpg
duplicity-inc.20160101T045912Z.to.20160101T050021Z.manifest.gpg
duplicity-full.20160101T045912Z.vol1.difftar.gpg
duplicity-inc.20160101T045912Z.to.20160101T050021Z.vol1.difftar.gpg
duplicity-full-signatures.20160101T045912Z.sigtar.gpg
duplicity-new-signatures.20160101T045912Z.to.20160101T050021Z.sigtar.gpg

$ ls -R data
data/scene:
1 2 3

--------------------------------------------------------------------------
$ duplicity collection-status --file-changed 1 file://./backup/scene

Local and Remote metadata are synchronized, no sync needed.
Last full backup date: Fri Jan 1 04:59:12 2016
............................
File: 1
Total number of backup: 2
 Type of backup set: Time: Type of file change:
                Full Fri Jan 1 04:59:12 2016 New
         Incremental Fri Jan 1 05:00:21 2016 Changed
............................

--------------------------------------------------------------------------
$ duplicity collection-status --file-changed 1 file:///full/path/to/backup/scene

............................
File: 1
Total number of backup: 0
 Type of backup set: Time: Type of file change:
............................