Why duplicity has no option to restore full backups ignoring missing signature files?

On 18.11.2013 23:41, Dan Flexy wrote:
> New question #239432 on Duplicity:
> https://answers.launchpad.net/duplicity/+question/239432
>
> In my case, the signature files were lost (after using --extra-clean without forward-thinking).
>
> But for many, keeping signature files on full backups might make no sense, as this metadata is surplus and only takes valuable disk space (these files could be pretty large!).
>
> So why duplicity is unable to restore full backups when there are no corresponding signature files?
>
> It is very weird, as it is totally capable to do so without these files.
>
> Thank you.
>

Dan,

can you elaborate? show a duplicity console output of a non working restore?

you are correct in the assumption that the clean command is merely supposed to delete files that are not essential to restoring. they are however needed for performant listing or incremental adding to a backup chain.

..ede/duply.net

I've tried to get you a console output and it worked... !

Apparently, I was fooled that list-current-files did not work without signatures.
I was under impression that if duplicity refuses to list files, they can't be restored.

So whilst no longer that critical, I guess my question could be re-phrased to:

"Why duplicity can not list files in a full backup when signature files are absent?"

# ls -la /tmp/dup/
-rwxr-xr-x 1 201 Nov 18 22:30 duplicity-full.20130701T020002Z.manifest.gpg
-rwxr-xr-x 1 2437421 Nov 18 22:30 duplicity-full.20130701T020002Z.vol1.difftar.gpg

# duplicity list-current-files file:///tmp/dup/

...
  File "/usr/lib/python2.7/dist-packages/duplicity/collections.py", line 974, in get_signature_chain_at_time
    raise CollectionsError("No signature chains found")
CollectionsError: No signature chains found

Many thanks