Description of problem:
Run dnf groups list and that's all.

Version-Release number of selected component:
dnf-0.4.5-1.fc20

Additional info:
reporter:       libreport-2.1.8
cmdline:        /usr/bin/python /usr/bin/dnf groups list
executable:     /usr/bin/dnf
kernel:         3.11.6-300.fc20.x86_64
runlevel:       N 5
type:           Python
uid:            1000

Truncated backtrace:
comps.py:109:_ui_text:KeyError: "KeyError: 'en_US.UTF-8'"

Traceback (most recent call last):
  File "/usr/bin/dnf", line 35, in <module>
    main.user_main(sys.argv[1:], exit_code=True)
  File "/usr/lib/python2.7/site-packages/dnf/cli/main.py", line 272, in user_main
    errcode = main(args)
  File "/usr/lib/python2.7/site-packages/dnf/cli/main.py", line 64, in main
    return _main(base, args)
  File "/usr/lib/python2.7/site-packages/dnf/cli/main.py", line 133, in _main
    result, resultmsgs = cli.run()
  File "/usr/lib/python2.7/site-packages/dnf/cli/cli.py", line 1305, in run
    return self.command.doCommand(self.base.basecmd, self.base.extcmds)
  File "/usr/lib/python2.7/site-packages/dnf/cli/commands.py", line 876, in doCommand
    return self.base.returnGroupLists(extcmds)
  File "/usr/lib/python2.7/site-packages/dnf/cli/cli.py", line 785, in returnGroupLists
    _out_grp(_('Installed Groups:'), group)
  File "/usr/lib/python2.7/site-packages/dnf/cli/cli.py", line 775, in _out_grp
    msg = '   %s' % group.ui_name
  File "/usr/lib/python2.7/site-packages/dnf/comps.py", line 121, in ui_name
    return self._ui_text(self.name, self.name_by_lang)
  File "/usr/lib/python2.7/site-packages/dnf/comps.py", line 109, in _ui_text
    t = dct[l]
KeyError: "KeyError: 'en_US.UTF-8'"

Local variables in innermost frame:
default: u'Network Servers'
dct: <libcomps.Dict object at 0x306bf18>
l: 'en_US.UTF-8'
self: <dnf.comps.Group object at 0x2ac44d0>