Failed to run bzr

lp:bzr (r6543)

All commands crash with below traceback.

Traceback (most recent call last):
  File "C:\DEVELOP\py_envs\bzr2.6\Scripts\bzr", line 114, in <module>
    library_state = bzrlib.initialize()
  File "C:\DEVELOP\py_envs\bzr2.6\lib\site-packages\bzrlib\__init__.py", line 226, in initialize
    state._start()
  File "C:\DEVELOP\py_envs\bzr2.6\lib\site-packages\bzrlib\library_state.py", line 98, in _start
    self._trace.__enter__()
  File "C:\DEVELOP\py_envs\bzr2.6\lib\site-packages\bzrlib\trace.py", line 654, in __enter__
    self._original_state = enable_default_logging()
  File "C:\DEVELOP\py_envs\bzr2.6\lib\site-packages\bzrlib\trace.py", line 286, in enable_default_logging
    bzr_log_file = _open_bzr_log()
  File "C:\DEVELOP\py_envs\bzr2.6\lib\site-packages\bzrlib\trace.py", line 247, in _open_bzr_log
    _rollover_trace_maybe(_bzr_log_filename)
  File "C:\DEVELOP\py_envs\bzr2.6\lib\site-packages\bzrlib\trace.py", line 191, in _rollover_trace_maybe
    osutils.rename(trace_fname, old_fname)
  File "C:\DEVELOP\py_envs\bzr2.6\lib\site-packages\bzrlib\osutils.py", line 466, in _rename_wrapper
    (old, new))
UnicodeDecodeError: 'ascii' codec can't decode byte 0x83 in position 0: ordinal not in range(128)

Bazaar (bzr) 2.6.0dev3
  Python interpreter: C:\DEVELOP\py_envs\bzr2.6\Scripts\python.exe 2.7.2
  Python standard library: C:\DEVELOP\py_envs\bzr2.6\lib
  Platform: Windows-7-6.1.7601-SP1
  bzrlib: C:\DEVELOP\py_envs\bzr2.6\lib\site-packages\bzrlib
  Bazaar configuration: C:/Users/iwata/AppData/Roaming/bazaar/2.0
  Bazaar log file: C:\Users\iwata\Documents\.bzr.log

--
This problem comes from several causes.

1. At first, bzr trys to rename .bzr.log to .bzr.log.old if the log file size is over the threshold.
    But this often fails. (One of major causes is that .bzr.log.old already exists, another is that tbzr or other bzr process locks it.)

2. Exception handler of osutils.rename has a problem about non-ascii characters. So bzr can't handle rename error correctly.