I just got tricked into checking this issue again, here's the backtrace.
Version is http://packages.debian.org/lenny-backports/bzr - 2.0.3-1~bpo50+1

this is a debug log for diagnosing/reporting problems in bzr
you can delete or truncate this file, or include sections in
bug reports to https://bugs.launchpad.net/bzr/+filebug

Mon 2010-11-01 20:17:26 +0000
0.127  bzr arguments: [u'--no-plugins', u'serve', u'--inet', u'--directory=/srv/bzr', u'--allow-writes']
0.262  encoding stdout as osutils.get_user_encoding() 'ANSI_X3.4-1968'
0.367  Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/smart/protocol.py", line 893, in accept_bytes
    _StatefulDecoder.accept_bytes(self, bytes)
  File "/usr/lib/python2.5/site-packages/bzrlib/smart/protocol.py", line 388, in accept_bytes
    self.state_accept()
  File "/usr/lib/python2.5/site-packages/bzrlib/smart/protocol.py", line 999, in _state_accept_expecting_message_part
    self.done()
  File "/usr/lib/python2.5/site-packages/bzrlib/smart/protocol.py", line 1037, in done
    raise errors.SmartMessageHandlerError(sys.exc_info())
SmartMessageHandlerError: The message handler raised an exception:
Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/smart/protocol.py", line 1035, in done
    self.message_handler.end_received()
  File "/usr/lib/python2.5/site-packages/bzrlib/smart/message.py", line 164, in end_received
    "Complete conventional request was received, but request "
SmartProtocolError: Generic bzr smart protocol error: Complete conventional request was received, but request handler has not finished reading.


1.970  Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/bzrlib/smart/request.py", line 326, in _call_converting_errors
    return callable(*args, **kwargs)
  File "/usr/lib/python2.5/site-packages/bzrlib/smart/request.py", line 132, in execute
    return self.do(*args)
  File "/usr/lib/python2.5/site-packages/bzrlib/smart/branch.py", line 49, in do
    return self.do_with_branch(branch, *args)
  File "/usr/lib/python2.5/site-packages/bzrlib/smart/branch.py", line 297, in do_with_branch
    branch_token = branch.lock_write(token=branch_token)
  File "/usr/lib/python2.5/site-packages/bzrlib/branch.py", line 2135, in lock_write
    return self.control_files.lock_write(token=token)
  File "/usr/lib/python2.5/site-packages/bzrlib/lockable_files.py", line 194, in lock_write
    token_from_lock = self._lock.lock_write(token=token)
  File "/usr/lib/python2.5/site-packages/bzrlib/lockdir.py", line 579, in lock_write
    return self.wait_lock()
  File "/usr/lib/python2.5/site-packages/bzrlib/lockdir.py", line 503, in wait_lock
    return self.attempt_lock()
  File "/usr/lib/python2.5/site-packages/bzrlib/lockdir.py", line 464, in attempt_lock
    result = self._attempt_lock()
  File "/usr/lib/python2.5/site-packages/bzrlib/lockdir.py", line 222, in _attempt_lock
    tmpname = self._create_pending_dir()
  File "/usr/lib/python2.5/site-packages/bzrlib/lockdir.py", line 280, in _create_pending_dir
    info_bytes = self._prepare_info()
  File "/usr/lib/python2.5/site-packages/bzrlib/lockdir.py", line 439, in _prepare_info
    user = config.user_email()
  File "/usr/lib/python2.5/site-packages/bzrlib/config.py", line 224, in user_email
    return extract_email_address(self.username())
  File "/usr/lib/python2.5/site-packages/bzrlib/config.py", line 252, in username
    name, email = _auto_user_id()
  File "/usr/lib/python2.5/site-packages/bzrlib/config.py", line 892, in _auto_user_id
    raise errors.BzrCommandError('Unable to determine your name.  '
BzrCommandError: Unable to determine your name.  Use "bzr whoami" to set it.

2.130  return code 0


We'd appreciate a work-around.