duplicity-team team mailing list archive

[Peter Schuller <peter.schuller@xxxxxxxxxxxx>]

Some more incremental investigation:

> Traceback (most recent call last):
>   File "./duplicity-bin", line 1197, in <module>
>     with_tempdir(main)
>   File "./duplicity-bin", line 1190, in with_tempdir
>     fn()
>   File "./duplicity-bin", line 1172, in main
>     incremental_backup(sig_chain)
>   File "./duplicity-bin", line 484, in incremental_backup
>     globals.backend)
>   File "./duplicity-bin", line 252, in write_multivol
>     globals.restart.setLastSaved(mf)
>   File "./duplicity-bin", line 1065, in setLastSaved
>     vi = mf.volume_info_dict[self.start_vol]
> KeyError: 0

In this case the relevant files are empty but existing:

-rw-r--r--  1 scode  scode  100902 Jul  7 18:41 duplicity-full-signatures.20090704T162538Z.sigtar.gz
-rw-r--r--  1 scode  scode     199 Jul  7 18:41 duplicity-full.20090704T162538Z.manifest
-rw-r--r--  1 scode  scode     181 Jul  7 18:41 duplicity-inc.20090704T162538Z.to.20090704T162600Z.manifest
-rw-r--r--  1 scode  scode      20 Jul  7 18:41 duplicity-new-signatures.20090704T162538Z.to.20090704T162600Z.sigtar.gz
-rw-------  1 scode  scode   41472 Jul  7 18:41 duplicity-new-signatures.20090704T162600Z.to.20090707T164117Z.sigtar.part
-rw-------  1 scode  scode     254 Jul  7 18:41 duplicity-inc.20090704T162600Z.to.20090707T164117Z.manifest.part
-rw-------  1 scode  scode       0 Jul  7 18:41 duplicity-new-signatures.20090707T164117Z.to.20090707T164131Z.sigtar.part
-rw-------  1 scode  scode       0 Jul  7 18:41 duplicity-inc.20090707T164117Z.to.20090707T164131Z.manifest.part
-rw-------  1 scode  scode       0 Jul  7 20:18 duplicity-new-signatures.20090707T164131Z.to.20090707T181854Z.sigtar.part
-rw-------  1 scode  scode       0 Jul  7 20:18 duplicity-inc.20090707T164131Z.to.20090707T181854Z.manifest.part
-rw-------  1 scode  scode       0 Jul  7 20:19 duplicity-new-signatures.20090707T181854Z.to.20090707T181904Z.sigtar.part
-rw-------  1 scode  scode       0 Jul  7 20:19 duplicity-inc.20090707T181854Z.to.20090707T181904Z.manifest.part
-rw-------  1 scode  scode       0 Jul  8 18:41 duplicity-new-signatures.20090707T181904Z.to.20090708T164157Z.sigtar.part
-rw-------  1 scode  scode       0 Jul  8 18:41 duplicity-inc.20090707T181904Z.to.20090708T164157Z.manifest.part
-rw-------  1 scode  scode       0 Jul  8 18:46 duplicity-new-signatures.20090708T164157Z.to.20090708T164634Z.sigtar.part
-rw-------  1 scode  scode       0 Jul  8 18:46 duplicity-inc.20090708T164157Z.to.20090708T164634Z.manifest.part
-rw-------  1 scode  scode       0 Jul  8 18:53 duplicity-new-signatures.20090708T164634Z.to.20090708T165356Z.sigtar.part
-rw-------  1 scode  scode       0 Jul  8 18:53 duplicity-inc.20090708T164634Z.to.20090708T165356Z.manifest.part
-rw-------  1 scode  scode       0 Jul  8 19:12 duplicity-new-signatures.20090708T165356Z.to.20090708T171215Z.sigtar.part
-rw-------  1 scode  scode       0 Jul  8 19:12 duplicity-inc.20090708T165356Z.to.20090708T171215Z.manifest.part
-rw-------  1 scode  scode       0 Jul  8 23:37 duplicity-new-signatures.20090708T171215Z.to.20090708T213729Z.sigtar.part
-rw-------  1 scode  scode       0 Jul  8 23:37 duplicity-inc.20090708T171215Z.to.20090708T213729Z.manifest.part

And indeed, the call to get_local_manifest() in duplicity-bin ends up
dispatching to Manifest().from_string(), which receives an empty
string, read from file.

As a result, the self.add_volume_info() in the loop.

If I understand things correctly (and I've always been fuzzy on these
parts of the code), a "manifest" represents volume information for
some set. In practice this is a set of volumes associated with a
"backup", either a full backup or an incremental which is part of a
chain.

In this case, the general issue is that the code fails for any
manifest that is completely empty because we cannot obtain meta-data
information for the "first" volume (start_vol) in
Restart.setLastSaved().

Question: Is the bug that we should handle empty manifests, or is the
bug that a manifast should never exist that is empty (other than as
transient data structures in memory)?

Reading later on we have:

        # Checkpoint after each volume so restart has a place to restart.
        # Note that until after the first volume, all files are temporary.
        if vol_num == 1:
            sig_outfp.to_partial()
            man_outfp.to_partial()
        else:
            sig_outfp.flush()
            man_outfp.flush()

This suggests to me the bug is the latter (since it's supposed to be
invisible) rather than the former, though at this time I'm not sure
why the attempt to make it invisible doesn't work.

-- 
/ Peter Schuller

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