I have also replicated the bug, on Ubuntu 14.04 deja-dup 30.0 duplicity 0.6.23 (haven't got a more recent version yet but David has), as a newly-created user with the default Déjà-Dup settings:
1. Perform the first full backup and check that the backup, the file signatures, and the manifest file have been successfully created: $ ls -l ~/deja-dup -rw------- 1 luke luke 171 Jan 16 00:51 duplicity-full.20170115T235149Z.manifest -rw------- 1 luke luke 48989 Jan 16 00:51 duplicity-full.20170115T235149Z.vol1.difftar.gz -rw------- 1 luke luke 9965 Jan 16 00:51 duplicity-full-signatures.20170115T235149Z.sigtar.gz 2. Uncompress the backup volume: $ gunzip --to-stdout duplicity-full.20170115T235149Z.vol1.difftar.gz > duplicity-full.20170115T235149Z.vol1.difftar $ ls -l ~/deja-dup -rw------- 1 luke luke 171 Jan 16 00:51 duplicity-full.20170115T235149Z.manifest -rw-rw-r-- 1 luke luke 480256 Jan 16 00:57 duplicity-full.20170115T235149Z.vol1.difftar -rw------- 1 luke luke 48989 Jan 16 00:51 duplicity-full.20170115T235149Z.vol1.difftar.gz -rw------- 1 luke luke 9965 Jan 16 00:51 duplicity-full-signatures.20170115T235149Z.sigtar.gz 3. Start the first incremental backup and witness the assertion error in duplicity that David reported: $ deja-dup --backup Traceback (most recent call last): File "/usr/bin/duplicity", line 1494, in <module> with_tempdir(main) File "/usr/bin/duplicity", line 1488, in with_tempdir fn() File "/usr/bin/duplicity", line 1337, in main do_backup(action) File "/usr/bin/duplicity", line 1370, in do_backup globals.archive_dir).set_values() File "/usr/lib/python2.7/dist-packages/duplicity/collections.py", line 697, in set_values self.get_backup_chains(partials + backend_filename_list) File "/usr/lib/python2.7/dist-packages/duplicity/collections.py", line 819, in get_backup_chains map(add_to_sets, filename_list) File "/usr/lib/python2.7/dist-packages/duplicity/collections.py", line 809, in add_to_sets if set.add_filename(filename): File "/usr/lib/python2.7/dist-packages/duplicity/collections.py", line 100, in add_filename (self.volume_name_dict, filename) AssertionError: ({1: 'duplicity-full.20170115T235149Z.vol1.difftar'}, 'duplicity-full.20170115T235149Z.vol1.difftar.gz') $ DEJA_DUP_DEBUG=1 deja-dup --backup > deja-dup.log1 # see attached file for details 4. Interestingly, duplicity already has checks to avoid considering files whose names don't look like they could be part of a backup set, as proven by the success and log file of the following incremental backup: $ ls -l ~/deja-dup -rw-rw-r-- 1 luke luke 0 Jan 16 01:08 assignment.odt -rw-rw-r-- 1 luke luke 0 Jan 16 01:08 creative-writing-syllabus.pdf -rw-rw-r-- 1 luke luke 0 Jan 16 01:08 duplicity-commandline-memo.txt -rw-rw-r-- 1 luke luke 0 Jan 16 01:08 duplicity-full-1995-movie.mkv.vol1.rar -rw------- 1 luke luke 171 Jan 16 00:51 duplicity-full.20170115T235149Z.manifest -rw------- 1 luke luke 48989 Jan 16 00:51 duplicity-full.20170115T235149Z.vol1.difftar.gz -rw------- 1 luke luke 9965 Jan 16 00:51 duplicity-full-signatures.20170115T235149Z.sigtar.gz $ DEJA_DUP_DEBUG=1 deja-dup --backup > deja-dup.log2 # see attached file for details (truncated to the interesting bits) So there's no need to come up with a brand-new extensive filename filter, it's already here, only improve it so it doesn't burp so hard when a backup volume is present in both compressed and uncompressed forms. ** Attachment added: "deja-dup.log1" https://bugs.launchpad.net/deja-dup/+bug/1652410/+attachment/4804855/+files/deja-dup.log1 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to deja-dup in Ubuntu. https://bugs.launchpad.net/bugs/1652410 Title: Undescriptive duplicity/collection-status error when the backup directory contains two volumes with different file names and same volume number in the same backup set Status in Déjà Dup: Triaged Status in deja-dup package in Ubuntu: New Bug description: Deja-dup has never worked for me (last 5 years) always errors. No after a new system reinstall 16.04 I was determined to get it up and running and learn about it's use,and perhaps recover some old data. Still fails with see attached text ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: deja-dup 34.2-0ubuntu1.1 ProcVersionSignature: Ubuntu 4.4.0-57.78-generic 4.4.35 Uname: Linux 4.4.0-57-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.4 Architecture: amd64 CurrentDesktop: Unity Date: Fri Dec 23 16:56:43 2016 ExecutablePath: /usr/bin/deja-dup InstallationDate: Installed on 2016-12-02 (21 days ago) InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) ProcEnviron: PATH=(custom, user) SHELL=/usr/bin/fish LANG=en_CA.UTF-8 LANGUAGE=en_CA:en XDG_RUNTIME_DIR=<set> SourcePackage: deja-dup UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/deja-dup/+bug/1652410/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp