Comment 28 for bug 681002

I appear to be getting the same problems with Ubuntu 12.10. It used to work fine. The issue suddenly appeared after cancelling a backup due to network problems.

Attempting to do incremental encrypted backup. DD prompts for password. Goes scanning. Reaches end of scanning. Prompts for password again. Repeat ad infinitum.

1) OSversion
Ubuntu 12.10 (32 bit)

2) DDversions
deja-dup 24.0-0ubuntu1
duplicity 0.6.19-0ubuntu2.2

3) DD gsettings
deja-dup.gsettings
org.gnome.DejaDup backend 'file'
org.gnome.DejaDup delete-after 84
org.gnome.DejaDup exclude-list ['/home/ross/.local/share/Trash']
org.gnome.DejaDup full-backup-period 90
org.gnome.DejaDup include-list ['$HOME']
org.gnome.DejaDup last-backup '2013-01-26T00:20:59.680505Z'
org.gnome.DejaDup last-restore ''
org.gnome.DejaDup last-run '2013-01-26T00:20:59.680505Z'
org.gnome.DejaDup nag-check '2012-12-06T01:55:55.372162Z'
org.gnome.DejaDup periodic false
org.gnome.DejaDup periodic-period 1
org.gnome.DejaDup prompt-check '2011-10-14T10:07:43.024981Z'
org.gnome.DejaDup root-prompt true
org.gnome.DejaDup welcomed false
org.gnome.DejaDup.File icon ''
org.gnome.DejaDup.File name ''
org.gnome.DejaDup.File path 'smb://rufus/backup/annie'
org.gnome.DejaDup.File relpath @ay []
org.gnome.DejaDup.File short-name ''
org.gnome.DejaDup.File type 'normal'
org.gnome.DejaDup.File uuid ''
org.gnome.DejaDup.Rackspace container 'TravelMate-2480'
org.gnome.DejaDup.Rackspace username ''
org.gnome.DejaDup.S3 bucket ''
org.gnome.DejaDup.S3 folder 'TravelMate-2480'
org.gnome.DejaDup.S3 id ''
org.gnome.DejaDup.U1 folder '/deja-dup/TravelMate-2480'

4) run DD to get debug log
The most relevant part appears to be

DUPLICITY: INFO 1
DUPLICITY: . GPG error detail: Traceback (most recent call last):
DUPLICITY: . File "/usr/bin/duplicity", line 1412, in <module>
DUPLICITY: . with_tempdir(main)
DUPLICITY: . File "/usr/bin/duplicity", line 1405, in with_tempdir
DUPLICITY: . fn()
DUPLICITY: . File "/usr/bin/duplicity", line 1281, in main
DUPLICITY: . sync_archive(decrypt)
DUPLICITY: . File "/usr/bin/duplicity", line 1081, in sync_archive
DUPLICITY: . copy_to_local(fn)
DUPLICITY: . File "/usr/bin/duplicity", line 1028, in copy_to_local
DUPLICITY: . gpg.GzipWriteFile(src_iter, tdp.name, size=sys.maxint)
DUPLICITY: . File "/usr/lib/python2.7/dist-packages/duplicity/gpg.py", line 371, in GzipWriteFile
DUPLICITY: . new_block = block_iter.next()
DUPLICITY: . File "/usr/bin/duplicity", line 1008, in next
DUPLICITY: . self.fileobj.close()
DUPLICITY: . File "/usr/lib/python2.7/dist-packages/duplicity/dup_temp.py", line 225, in close
DUPLICITY: . assert not self.fileobj.close()
DUPLICITY: . File "/usr/lib/python2.7/dist-packages/duplicity/gpg.py", line 239, in close
DUPLICITY: . self.gpg_failed()
DUPLICITY: . File "/usr/lib/python2.7/dist-packages/duplicity/gpg.py", line 206, in gpg_failed
DUPLICITY: . raise GPGError, msg
DUPLICITY: . GPGError: GPG Failed, see log below:
DUPLICITY: . ===== Begin GnuPG log =====
DUPLICITY: . gpg: CAST5 encrypted data
DUPLICITY: . gpg: encrypted with 1 passphrase
DUPLICITY: . gpg: decryption failed: bad key
DUPLICITY: . ===== End GnuPG log =====
DUPLICITY: .
DUPLICITY: .

DUPLICITY: ERROR 31 GPGError
DUPLICITY: . GPGError: GPG Failed, see log below:
DUPLICITY: . ===== Begin GnuPG log =====
DUPLICITY: . gpg: CAST5 encrypted data
DUPLICITY: . gpg: encrypted with 1 passphrase
DUPLICITY: . gpg: decryption failed: bad key
DUPLICITY: . ===== End GnuPG log =====
DUPLICITY: .

The log claims that the passphrase is incorrect, but I used gpg to confirm I could decrypt the manifest with the same passphrase.

I've submitted a bug report for this.