Hi Michael Indeed the problem relates to the locale setting ( with unattended-upgrade 0.86.3 )
export LC_ALL=C unattended-upgrade --help Usage: unattended-upgrade [options] ( works as expected) setting a different locale brings an error which seems python2->python3 related: export LC_ALL=fr_FR.utf-8 unattended-upgrade --help Traceback (most recent call last): File "/usr/bin/unattended-upgrade", line 1424, in <module> (options, args) = parser.parse_args() File "/usr/lib/python3.4/optparse.py", line 1386, in parse_args stop = self._process_args(largs, rargs, values) File "/usr/lib/python3.4/optparse.py", line 1426, in _process_args self._process_long_opt(rargs, values) File "/usr/lib/python3.4/optparse.py", line 1500, in _process_long_opt option.process(opt, value, values, self) File "/usr/lib/python3.4/optparse.py", line 784, in process self.action, self.dest, opt, value, values, parser) File "/usr/lib/python3.4/optparse.py", line 806, in take_action parser.print_help() File "/usr/lib/python3.4/optparse.py", line 1646, in print_help file.write(self.format_help()) File "/usr/lib/python3.4/optparse.py", line 1634, in format_help result.append(self.format_option_help(formatter)) File "/usr/lib/python3.4/optparse.py", line 1614, in format_option_help result.append(OptionContainer.format_option_help(self, formatter)) File "/usr/lib/python3.4/optparse.py", line 1060, in format_option_help result.append(formatter.format_option(option)) File "/usr/lib/python3.4/optparse.py", line 321, in format_option help_text = self.expand_default(option) File "/usr/lib/python3.4/optparse.py", line 293, in expand_default return option.help.replace(self.default_tag, str(default_value)) TypeError: 'str' does not support the buffer interface -- /* http://parttimelog.wordpress.com/ Part time pictures */