Backup fails silently when target is full (sftp, verbosity=4)

[Daniel Hahler]

I have just noticed that I am missing backups for the last days, when the backup space has run full.

It is 100% full currently, and a backup looks like this in the cron mails:
--- Start running command BKP at 02:27:26.969 ---
Reading globbing filelist /etc/duply/moby/exclude
Local and Remote metadata are synchronized, no sync needed.
Warning, found incomplete backup sets, probably left from aborted session
Last full backup date: Thu Dec 2 02:24:07 2010
Last full backup is too old, forcing full backup
Warning, found incomplete backup sets, probably left from aborted session
--------------[ Backup Statistics ]--------------
StartTime 1294450054.25 (Sat Jan 8 02:27:34 2011)
EndTime 1294470492.74 (Sat Jan 8 08:08:12 2011)
ElapsedTime 20438.48 (5 hours 40 minutes 38.48 seconds)
SourceFiles 555664
SourceFileSize 39279601888 (36.6 GB)
NewFiles 555664
NewFileSize 39279601448 (36.6 GB)
DeletedFiles 0
ChangedFiles 0
ChangedFileSize 0 (0 bytes)
ChangedDeltaSize 0 (0 bytes)
DeltaEntries 555664
RawDeltaSize 38926722865 (36.3 GB)
TotalDestinationSizeChange 26026186715 (24.2 GB)
Errors 0
-------------------------------------------------

--- Finished state OK at 08:22:45.937 - Runtime 05:55:18.967 ---

The verbose log (verbosity=9) contains stanzas like this:
AsyncScheduler: running task synchronously (asynchronicity disabled)
Running 'sftp -oServerAliveInterval=15 -oServerAliveCountMax=2 <email address hidden>' (attempt #1)
State = sftp, Before = 'Connected to u123.your-backup.de.'
sftp command: 'put "/tmp/duplicity-2pKK0d-tempdir/mktemp-GhWo7s-497" "moby//duplicity-full.20110108T173127Z.vol496.difftar.gpg"'
State = sftp, Before = 'put "/tmp/duplicity-2pKK0d-tempdir/mktemp-GhWo7s-497" "moby//duplicity-full.20110108T173127Z.vol496.difftar.gpg"
Uploading /tmp/duplicity-2pKK0d-tempdir/mktemp-GhWo7s-497 to /moby//duplicity-full.20110108T173127Z.vol496.difftar.gpg
remote open("/moby//duplicity-full.20110108T173127Z.vol496.difftar.gpg"): Failure'
State = sftp, Before = 'quit'
Deleting /tmp/duplicity-2pKK0d-tempdir/mktemp-GhWo7s-497
Forgetting temporary file /tmp/duplicity-2pKK0d-tempdir/mktemp-GhWo7s-497
AsyncScheduler: task completed successfully

Apparently the "remote open("/moby//duplicity-full.20110108T173127Z.vol496.difftar.gpg"): Failure'" error is not detected properly.

I am using duplicity 0.6.11 and a sftp backend.