duplicity cannot back up files from Russian file directory

[Impact]

Any user of the gio backend in duplicity (used by Deja Dup) backing up to a directory with utf8 characters in it is unable to complete a single backup.

[Test Case]

mkdir /tmp/source
echo test > /tmp/source/test
mkdir /tmp/Ж
duplicity --gio --no-encryption /tmp/source file:///tmp/Ж

[Regression Potential]

The upstream patch to fix this mostly affects various exception or logging code paths. But each one is pretty simple change (just upgrading ascii to unicode).

[Original Report]

After upgrading to Ubuntu 14.04 from 13.10, Duplicity cannot backup files. The location it will backup and the location to backup have both Russian characters in path. I believe this is the reason of the problem.

After failure, duplicity shows this log:
------------------------------
Traceback (most recent call last):
  File "/usr/bin/duplicity", line 1494, in <module>
    with_tempdir(main)
  File "/usr/bin/duplicity", line 1488, in with_tempdir
    fn()
  File "/usr/bin/duplicity", line 1337, in main
    do_backup(action)
  File "/usr/bin/duplicity", line 1470, in do_backup
    incremental_backup(sig_chain)
  File "/usr/bin/duplicity", line 637, in incremental_backup
    globals.backend)
  File "/usr/bin/duplicity", line 424, in write_multivol
    (tdp, dest_filename, vol_num)))
  File "/usr/lib/python2.7/dist-packages/duplicity/asyncscheduler.py", line 145, in schedule_task
    return self.__run_synchronously(fn, params)
  File "/usr/lib/python2.7/dist-packages/duplicity/asyncscheduler.py", line 171, in __run_synchronously
    ret = fn(*params)
  File "/usr/bin/duplicity", line 423, in <lambda>
    async_waiters.append(io_scheduler.schedule_task(lambda tdp, dest_filename, vol_num: put(tdp, dest_filename, vol_num),
  File "/usr/bin/duplicity", line 314, in put
    backend.put(tdp, dest_filename)
  File "/usr/lib/python2.7/dist-packages/duplicity/backends/giobackend.py", line 145, in put
    self.copy_file('put', source_file, target_file)
  File "/usr/lib/python2.7/dist-packages/duplicity/backend.py", line 330, in iterate
    return fn(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/duplicity/backends/giobackend.py", line 130, in copy_file
    log.Info(_("Writing %s") % target.get_parse_name())
UnicodeDecodeError: 'ascii' codec can't decode byte 0xd0 in position 36: ordinal not in range(128)

-------------------------------
I believe the related script shall be fixed with "u" prefix, as explained here:
http://stackoverflow.com/questions/9644099/python-ascii-codec-cant-decode-byte

Ozgur

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: duplicity 0.6.23-1ubuntu4
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic i686
ApportVersion: 2.14.1-0ubuntu3
Architecture: i386
CurrentDesktop: Unity
Date: Tue Apr 29 01:37:39 2014
SourcePackage: duplicity
UpgradeStatus: Upgraded to trusty on 2014-04-18 (10 days ago)