OverflowError: join() is too long for a Python string

[duplicity]

# duplicity --version
duplicity 0.6.19

# duplicity incremental --no-encryption /storage file:///ba
Local and Remote metadata are synchronized, no sync needed.
Last full backup left a partial set, restarting.
Last full backup date: Mon May 21 08:35:03 2012
RESTART: Volumes 62030 to 62030 failed to upload before termination.
         Restarting backup at volume 62030.
Restarting after volume 62029, file data/data_backup/blogI.tar, block 7463456
Traceback (most recent call last):
  File "/usr/bin/duplicity", line 1391, in ?
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1384, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1354, in main
    full_backup(col_stats)
  File "/usr/bin/duplicity", line 500, in full_backup
    globals.backend)
  File "/usr/bin/duplicity", line 346, in write_multivol
    restart_position_iterator(tarblock_iter)
  File "/usr/bin/duplicity", line 222, in restart_position_iterator
    while tarblock_iter.next():
  File "/usr/lib64/python2.4/site-packages/duplicity/diffdir.py", line 504, in n ext
    result = self.process_continued(size)
  File "/usr/lib64/python2.4/site-packages/duplicity/diffdir.py", line 676, in p rocess_continued
    data, last_block = self.get_data_block(self.process_fp, size - 512)
  File "/usr/lib64/python2.4/site-packages/duplicity/diffdir.py", line 662, in g et_data_block
    if fp.close():
  File "/usr/lib64/python2.4/site-packages/duplicity/diffdir.py", line 431, in c lose
    self.callback(self.sig_gen.getsig(), *self.extra_args)
  File "/usr/lib64/python2.4/site-packages/duplicity/librsync.py", line 214, in getsig
    return ''.join(self.sigstring_list)
OverflowError: join() is too long for a Python string