tries to decode debian/changelog as ascii, and fails when it's not

cat <<EOF > debian/changelog
  * Revert "power-cog" to combined design (System-Devices indicator)
    {dark,light}/…/system-devices-panel{,-alert,-warming} (LP: #844049)
EOF

bzr: ERROR: exceptions.UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 105: ordinal not in range(128)

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 946, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1150, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 699, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 721, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 135, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 165, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/builtins.py", line 3316, in run
    lossy=lossy)
  File "/usr/lib/python2.7/dist-packages/bzrlib/decorators.py", line 217, in write_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/workingtree_4.py", line 209, in commit
    result = WorkingTree.commit(self, message, revprops, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/decorators.py", line 217, in write_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/mutabletree.py", line 210, in commit
    *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commit.py", line 289, in commit
    lossy=lossy)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 131, in run
    self.cleanups, self.func, self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 165, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commit.py", line 440, in _commit
    self.rev_id = self.builder.commit(self.message)
  File "/usr/lib/python2.7/dist-packages/bzrlib/vf_repository.py", line 198, in commit
    self.new_inventory, self._config)
  File "/usr/lib/python2.7/dist-packages/bzrlib/vf_repository.py", line 1062, in add_revision
    self._add_revision(rev)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 105: ordinal not in range(128)

You can report this problem to Bazaar's developers by running
    apport-bug /var/crash/bzr.1000.2011-09-19T06:10.crash
if a bug-reporting window does not automatically appear.