I've checked the [popen4 code](https://github.com/opscode/chef/blob/master/lib/chef/mixin/command/unix.rb#L56).

It seems popen4 set ``LC_ALL`` to ``C`` if ``LC_ALL`` key is not set.

My implementation is to achieve to select the preferred locale in order, ``locale`` or ``LC_ALL``, or ``LANG`` (This is just fool-proof impl.).

If this violates the CHEF code policy, I'll replace the above code with ``run_opts[:environment]["LC_ALL"]  = nil``.