Déjà Dup backup failing with python stack trace on Ubuntu 16.04 [duplicate]

Question

I'm running Ubuntu 16.04 and I've been unable to backup my home directory for several days now. Every time Déjà Dup runs it fails with the following stack trace:

Traceback (most recent call last):
  File "/usr/bin/duplicity", line 1532, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1526, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1380, in main
    do_backup(action)
  File "/usr/bin/duplicity", line 1508, in do_backup
    incremental_backup(sig_chain)
  File "/usr/bin/duplicity", line 653, in incremental_backup
    bytes_written = dummy_backup(tarblock_iter)
  File "/usr/bin/duplicity", line 232, in dummy_backup
    while tarblock_iter.next():
  File "/usr/lib/python2.7/dist-packages/duplicity/diffdir.py", line 523, in next
    result = self.process(self.input_iter.next())
  File "/usr/lib/python2.7/dist-packages/duplicity/diffdir.py", line 195, in get_delta_iter
    for new_path, sig_path in collated:
  File "/usr/lib/python2.7/dist-packages/duplicity/diffdir.py", line 286, in collate2iters
    relem2 = riter2.next()
  File "/usr/lib/python2.7/dist-packages/duplicity/diffdir.py", line 354, in combine_path_iters
    refresh_triple_list(triple_list)
  File "/usr/lib/python2.7/dist-packages/duplicity/diffdir.py", line 341, in refresh_triple_list
    new_triple = get_triple(old_triple[1])
  File "/usr/lib/python2.7/dist-packages/duplicity/diffdir.py", line 327, in get_triple
    path = path_iter_list[iter_index].next()
  File "/usr/lib/python2.7/dist-packages/duplicity/diffdir.py", line 239, in sigtar2path_iter
    for tarinfo in tf:
  File "/usr/lib/python2.7/tarfile.py", line 2508, in next
    tarinfo = self.tarfile.next()
  File "/usr/lib/python2.7/tarfile.py", line 2350, in next
    raise ReadError("unexpected end of data")
ReadError: unexpected end of data

Anybody have any ideas about how I can get around this problem? I checked my disk space with df and nothing is full. It used to run fine, but just mysteriously stopped working. The last file in my backup directory is:

duplicity-new-signatures.20170518T071743Z.to.20170525T071808Z.sigtar.gz

Thanks in advance for any help.