Bug 1492288

Same for me

backup file on external hdd over USB 3.0

Tried to stop auto backup for a day, then after 2 updates to testing and manually start backup it finished with success. No idea what package fixed it. I set to auto backup and wait for traceback.

Interesting, it still traceback when auto backup is on, and succeed in case I disable auto backup and start manually. Weird.

Same here.
duplicity-0.7.13.1-2.fc26.x86_64
Auto backup on external USB 3 HD
Encryption enabled.

Traceback (most recent call last):
  File "/usr/bin/duplicity", line 1540, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1534, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1385, in main
    do_backup(action)
  File "/usr/bin/duplicity", line 1410, in do_backup
    globals.archive_dir).set_values()
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 710, in set_values
    self.get_backup_chains(partials + backend_filename_list)
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 836, in get_backup_chains
    add_to_sets(f)
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 824, in add_to_sets
    if set.add_filename(filename):
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 101, in add_filename
    self.set_manifest(filename)
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 148, in set_manifest
    self.set_files_changed()
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 128, in set_files_changed
    mf = self.get_manifest()
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 250, in get_manifest
    return self.get_local_manifest()
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 224, in get_local_manifest
    return manifest.Manifest().from_string(manifest_buffer)
  File "/usr/lib64/python2.7/site-packages/duplicity/manifest.py", line 215, in from_string
    vi = VolumeInfo().from_string(match.group(1))
MemoryError

Here is the upstream bug for this

https://bugs.launchpad.net/ubuntu/+source/duplicity/+bug/1727653

This is fixed by 0.7.15, which I just tested, which is in updates-testing, see bug #1512733

Yesterday I've installed 0.7.15, the full backup succeded.

Today the incremental backup has stopped with

Traceback (innermost last):
  File "/usr/bin/duplicity", line 1559, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1545, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1394, in main
    do_backup(action)
  File "/usr/bin/duplicity", line 1526, in do_backup
    check_last_manifest(col_stats)  # not needed for full backup
  File "/usr/bin/duplicity", line 1228, in check_last_manifest
    last_backup_set.check_manifests()
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 208, in check_manifests
    remote_manifest = self.get_remote_manifest()
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 249, in get_remote_manifest
    return manifest.Manifest().from_string(manifest_buffer)
  File "/usr/lib64/python2.7/site-packages/duplicity/manifest.py", line 202, in from_string
    vi = VolumeInfo().from_string(match.group(1))
  File "/usr/lib64/python2.7/site-packages/duplicity/manifest.py", line 390, in from_string
    linelist = s.strip().split("
")
 MemoryError

Still happens for me with Fedora 27 Duplicity 0.7.15

Same here for fedora 27 w/ duplicity-0.7.15-1.fc27.x86_64 on afp:// mount, was the same on smb:// mount.

Also for me, see discussion with upstream at https://bugs.launchpad.net/ubuntu/+source/duplicity/+bug/1730451

A me too. F 27 with duplicity  0.7.15-1.fc27 Slightly different backtrace.

Traceback (innermost last):
  File "/usr/bin/duplicity", line 1559, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1545, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1394, in main
    do_backup(action)
  File "/usr/bin/duplicity", line 1420, in do_backup
    action).set_values()
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 720, in set_values
    self.get_backup_chains(partials + backend_filename_list)
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 846, in get_backup_chains
    add_to_sets(f)
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 834, in add_to_sets
    if set.add_filename(filename):
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 102, in add_filename
    self.set_manifest(filename)
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 153, in set_manifest
    self.set_files_changed()
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 129, in set_files_changed
    mf = self.get_manifest()
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 256, in get_manifest
    return self.get_local_manifest()
  File "/usr/lib64/python2.7/site-packages/duplicity/collections.py", line 234, in get_local_manifest
    return manifest.Manifest().from_string(manifest_buffer)
  File "/usr/lib64/python2.7/site-packages/duplicity/manifest.py", line 202, in from_string
    vi = VolumeInfo().from_string(match.group(1))
 MemoryError

Another me too? 
Different backtrace on automatic incremental backup

Fedora 27, duplicity 0.7.16.1.fc27, kernel 4.14.14-300.fc27.x86_64

Traceback (innermost last):
  File "/usr/bin/duplicity", line 1559, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1545, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1394, in main
    do_backup(action)
  File "/usr/bin/duplicity", line 1527, in do_backup
    incremental_backup(sig_chain)
  File "/usr/bin/duplicity", line 669, in incremental_backup
    globals.backend)
  File "/usr/bin/duplicity", line 430, in write_multivol
    globals.volsize)
  File "/usr/lib64/python2.7/site-packages/duplicity/gpg.py", line 385, in GPGWriteFile
    data = block_iter.next().data
  File "/usr/lib64/python2.7/site-packages/duplicity/diffdir.py", line 520, in next
    result = self.process_continued()
  File "/usr/lib64/python2.7/site-packages/duplicity/diffdir.py", line 700, in process_continued
    data, last_block = self.get_data_block(self.process_fp)
  File "/usr/lib64/python2.7/site-packages/duplicity/diffdir.py", line 684, in get_data_block
    buf = fp.read(read_size)
  File "/usr/lib64/python2.7/site-packages/duplicity/librsync.py", line 88, in read
    self._add_to_outbuf_once()
  File "/usr/lib64/python2.7/site-packages/duplicity/librsync.py", line 98, in _add_to_outbuf_once
    self._add_to_inbuf()
  File "/usr/lib64/python2.7/site-packages/duplicity/librsync.py", line 113, in _add_to_inbuf
    assert not self.infile.close()
  File "/usr/lib64/python2.7/site-packages/duplicity/diffdir.py", line 440, in close
    self.callback(self.sig_gen.getsig(), *self.extra_args)
  File "/usr/lib64/python2.7/site-packages/duplicity/librsync.py", line 232, in getsig
    return ''.join(self.sigstring_list)
 MemoryError

One more thing: backup is to Samba share, and broke only after upgrade to Fedora 27 (from 26)

Another me too, same stacktrace as in comment 11

*** Bug 1544191 has been marked as a duplicate of this bug. ***

This seems to be resolved for me (for now). Found that my backup configuration was including a very large sub-directory in my ~/Downloads folder that was explicitly excluded, yet was picked up by the backup. Re-did the configuration and now things are fine. Makes me suspect that at least in my case the volume to be backed up was an issue, or perhaps just re-doing the backup configuration.

Excellent!