Scratch what I said in https://bugs.python.org/issue36837?@ok_message=msg%20342005%20created%0Aissue%2036837%20message_count%2C%20messages%20edited%20ok&@template=item#msg342005

GNU msgfmt does extract the charset correctly.  (My previous test failed to write any output so it was using the .mo file I had written out with msgfmt.py.  I realized that this morning when I figured out why my C test program wasn't finding any message catalog.

For reference the three ways to extract strings with the three tools are:
* pygettext.py test.py
* pybabel extract -o messages.pot test.py
* xgettext test.py -o messages.pot test.py

and the three ways to generate catalogs via the three tools are:
* msgfmt3.7.py  es_MX/LC_MESSAGES/domain.po
* msgfmt es_MX/LC_MESSAGES/testc.po -o es_MX/LC_MESSAGES/testc.mo
* pybabel compile -D test -d . [--use-fuzzy]