Comment 2 for bug 1013387

A reliable way to reproduce is:
$ LANG=junk junk
Sorry, command-not-found has crashed! Please file a bug report at:
https://bugs.launchpad.net/command-not-found/+filebug
Please include the following information with the report:

command-not-found version: 0.3
Python version: 3.2.3 final 0
Distributor ID: Ubuntu
Description: Ubuntu 12.10
Release: 12.10
Codename: quantal
Exception information:

unsupported locale setting
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 69, in main
    enable_i18n()
  File "/usr/lib/command-not-found", line 40, in enable_i18n
    locale.setlocale(locale.LC_ALL, '')
  File "/usr/lib/python3.2/locale.py", line 541, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting

Yes, probably no one would set LANG to "junk". But people may misspell locales and see the above daunting error message.