command-not-found when login \udc8b

[Erwen Yu]

command-not-found 版本：0.3
Python 版本：3.4.3 final 0
Distributor ID: Ubuntu
Description: Ubuntu 14.04 LTS
Release: 14.04
Codename: trusty
额外信息：

'utf-8' codec can't encode character '\udc8b' in position 1: surrogates not allowed
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/CommandNotFound/util.py", line 24, in crash_guard
    callback()
  File "/usr/lib/command-not-found", line 90, in main
    if not cnf.advise(args[0], options.ignore_installed) and not options.no_failure_msg:
  File "/usr/lib/python3/dist-packages/CommandNotFound/CommandNotFound.py", line 265, in advise
    packages = self.getPackages(command)
  File "/usr/lib/python3/dist-packages/CommandNotFound/CommandNotFound.py", line 157, in getPackages
    result.update([(pkg, db.component) for pkg in db.lookup(command)])
  File "/usr/lib/python3/dist-packages/CommandNotFound/CommandNotFound.py", line 85, in lookup
    result = self.db.lookup(command)
  File "/usr/lib/python3/dist-packages/CommandNotFound/CommandNotFound.py", line 41, in lookup
    key = key.encode('utf-8')
UnicodeEncodeError: 'utf-8' codec can't encode character '\udc8b' in position 1: surrogates not allowed