fails to backup

[Timski]

deja-dup backups some files and then exits with following error message

Traceback (most recent call last):
  File "/usr/bin/duplicity", line 1411, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1404, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1379, in main
    full_backup(col_stats)
  File "/usr/bin/duplicity", line 509, in full_backup
    globals.backend)
  File "/usr/bin/duplicity", line 386, in write_multivol
    globals.gpg_profile, globals.volsize)
  File "/usr/lib/python2.7/dist-packages/duplicity/gpg.py", line 327, in GPGWriteFile
    bytes_to_go = data_size - get_current_size()
  File "/usr/lib/python2.7/dist-packages/duplicity/gpg.py", line 320, in get_current_size
    return os.stat(filename).st_size
OSError: [Errno 2] No such file or directory: '/home/tim/.cache/deja-dup/tmp/duplicity-eoJhZh-tempdir/mktemp-RpMdBq-24'

I'm using
Ubuntu Raring Ringtail (development branch)
deja-dup 25.5-0ubuntu1
duplicity 0.6.21-0ubuntu1

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/tmp/deja-dup.gsettings

org.gnome.DejaDup backend 'file'
org.gnome.DejaDup delete-after 0
org.gnome.DejaDup exclude-list ['/home/tim/.local/share/Trash']
org.gnome.DejaDup full-backup-period 90
org.gnome.DejaDup include-list ['/home/tim']
org.gnome.DejaDup last-backup '2013-03-22T12:09:33.361212Z'
org.gnome.DejaDup last-restore '2012-12-22T02:01:09.090993Z'
org.gnome.DejaDup last-run '2013-03-22T12:09:33.361212Z'
org.gnome.DejaDup nag-check '2013-01-24T05:03:32.879047Z'
org.gnome.DejaDup periodic true
org.gnome.DejaDup periodic-period 7
org.gnome.DejaDup prompt-check '2013-01-23T23:23:12.723530Z'
org.gnome.DejaDup root-prompt true
org.gnome.DejaDup welcomed true
org.gnome.DejaDup.File icon '. GThemedIcon drive-harddisk-usb drive-harddisk drive'
org.gnome.DejaDup.File name 'WDC WD75 00BPKT-00PK4T0: Beate'
org.gnome.DejaDup.File path '/home/tim/deja-dup'
org.gnome.DejaDup.File relpath b'brussel'
org.gnome.DejaDup.File short-name 'Beate'
org.gnome.DejaDup.File type 'volume'
org.gnome.DejaDup.File uuid '1425bdc1-3529-443d-a72a-fa67704d02d7'
org.gnome.DejaDup.Rackspace container 'brussel'
org.gnome.DejaDup.Rackspace username ''
org.gnome.DejaDup.S3 bucket ''
org.gnome.DejaDup.S3 folder 'brussel'
org.gnome.DejaDup.S3 id ''
org.gnome.DejaDup.U1 folder '/deja-dup/brussel'

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can't find a /tmp/deja-dup.log