duplicity "CollectionsError: No backup chains found"

Question

I'm using duplicity 0.7.06 to back up and 0.7.17 to restore a duplicity backup. But I'm getting the error "No backup chains found" when trying to restore a directory from it.

I'm not sure what that error signifies though.

The backup is made like this (and there are no errors from this):

duplicity --no-encryption --full-if-older-than 10D /path/to/dir s3+http://my-s3-bucket/duplicity/dir

And I can see duplicity archives if I list them:

~$ s3cmd ls s3://my-s3-bucket/duplicity/dir/
2019-05-12 15:51     19505   s3://my-s3-bucket/duplicity/dir/duplicity-full-signatures.20190512T155147Z.sigtar.gz
2019-05-12 15:51       724   s3://my-s3-bucket/duplicity/dir/duplicity-full.20190512T155147Z.manifest
2019-05-12 15:51    728333   s3://my-s3-bucket/duplicity/dir/duplicity-full.20190512T155147Z.vol1.difftar.gz

I'm trying to restore it like this:

duplicity --file-to-restore path/to/dir s3+http://my-s3-bucket/duplicity /home/restored/dir

The error I'm getting is:

duplicity 0.7.17 (February 26, 2018)
Args: /usr/bin/duplicity --file-to-restore path/to/dir s3+http://my-s3-bucket/duplicity /home/restored/dir
Linux machinename 4.15.0-48-generic #51-Ubuntu SMP Wed Apr 3 08:28:49 UTC 2019 x86_64 x86_64
/usr/bin/python2 2.7.15rc1 (default, Nov 12 2018, 14:31:15) 
[GCC 7.3.0]
================================================================================
Using temporary directory /tmp/duplicity-Zu29z3-tempdir
Temp has 30699757568 available, backup will use approx 272629760.
Local and Remote metadata are synchronized, no sync needed.
Last full backup date: none
Traceback (innermost last):
  File "/usr/bin/duplicity", line 1555, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1541, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1393, in main
    do_backup(action)
  File "/usr/bin/duplicity", line 1472, in do_backup
    restore(col_stats)
  File "/usr/bin/duplicity", line 728, in restore
    restore_get_patched_rop_iter(col_stats)):
  File "/usr/bin/duplicity", line 750, in restore_get_patched_rop_iter
    backup_chain = col_stats.get_backup_chain_at_time(time)
  File "/usr/lib/python2.7/dist-packages/duplicity/collections.py", line 974, in get_backup_chain_at_time
    raise CollectionsError("No backup chains found")
 CollectionsError: No backup chains found

Answer 1

your restore command from above

duplicity --file-to-restore path/to/dir s3+http://my-s3-bucket/duplicity /home/restored/dir

lacks '/dir' at the end of the s3:// url. if it doesn't find your backups after adding it i suggest joining the duplicity mailing list and posting it there so we can try to find your issue in more detail.

..ede/duply.net

Answer 2

Following a clue in an answer from ede, I modified my restore line to add the name of the directory I wanted to restore to the end of the s3:// url:

s3+http://my-s3-bucket/duplicity/dir /home/restored

This then found the backup chain, but said it couldn't find "dir" in it.

I then tried removing the --file-to-restore switch to make the command as follows:

duplicity --no-encryption s3+http://my-s3-bucket/duplicity/dir /home/restored/dir

This worked.

---

As an aside, even when I've read the man page and looked at some examples, I find it hard to come up with a way of remembering how to correctly restore files from a duplicity archive. If anyone has a neat way of explaining how duplicity works relating to file paths and chains, I'd be grateful.