Steps to reproduce:
* Start Backups, aka Deja Dup Backup Tool (already configured to back up to location on second harddrive)
* Click "Back Up Now..."
* Wait for backup to complete
What should happen:
* Notification that backup is complete
* Restoring the backup succeeds
What happens instead:
* Notification that an error occurred
* Error window pops up (message below)
* Restoring the backup succeeds (despite the error)
Notes:
* The error message also pops up after automatic (scheduled) backups and automatic (scheduled) validation tests
Error message:
```
Traceback (innermost last):
File "/usr/bin/duplicity", line 1566, in <module>
with_tempdir(main)
File "/usr/bin/duplicity", line 1552, in with_tempdir
fn()
File "/usr/bin/duplicity", line 1401, in main
do_backup(action)
File "/usr/bin/duplicity", line 1480, in do_backup
restore(col_stats)
File "/usr/bin/duplicity", line 736, in restore
restore_get_patched_rop_iter(col_stats)):
File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line 558, in Write_ROPaths
for ropath in rop_iter:
File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line 521, in integrate_patch_iters
for patch_seq in collated:
File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line 389, in yield_tuples
setrorps(overflow, elems)
File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line 378, in setrorps
elems[i] = iter_list[i].next()
File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line 107, in filter_path_iter
for path in path_iter:
File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line 121, in difftar2path_iter
tarinfo_list = [tar_iter.next()]
File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line 339, in next
self.set_tarfile()
File "/usr/lib/python2.7/dist-packages/duplicity/patchdir.py", line 333, in set_tarfile
self.current_fp = self.fileobj_iter.next()
File "/usr/bin/duplicity", line 773, in get_fileobj_iter
manifest.volume_info_dict[vol_num])
File "/usr/bin/duplicity", line 816, in restore_get_enc_fileobj
fileobj = tdp.filtered_open_with_delete("rb")
File "/usr/lib/python2.7/dist-packages/duplicity/dup_temp.py", line 120, in filtered_open_with_delete
fh = FileobjHooked(path.DupPath.filtered_open(self, mode))
File "/usr/lib/python2.7/dist-packages/duplicity/path.py", line 779, in filtered_open
return gpg.GPGFile(False, self, gpg_profile)
File "/usr/lib/python2.7/dist-packages/duplicity/gpg.py", line 224, in __init__
'logger': self.logger_fp})
File "/usr/lib/python2.7/dist-packages/duplicity/gpginterface.py", line 374, in run
create_fhs, attach_fhs)
File "/usr/lib/python2.7/dist-packages/duplicity/gpginterface.py", line 420, in _attach_fork_exec
process.thread.start()
File "/usr/lib/python2.7/threading.py", line 736, in start
_start_new_thread(self.__bootstrap, ())
error: can't start new thread
```