Loads translations from `gettext`'s locale tree

    Locale tree is similar to system's ``/usr/share/locale``, like::

        {directory}/{lang}/LC_MESSAGES/{domain}.mo

    Three steps are required to have your app translated:

    1. Generate POT translation file::

        xgettext --language=Python --keyword=_:1,2 -d mydomain file1.py file2.html etc

    2. Merge against existing POT file::

        msgmerge old.po mydomain.po > new.po

    3. Compile::

        msgfmt mydomain.po -o {directory}/pt_BR/LC_MESSAGES/mydomain.mo

def load_gettext_translations(directory: str, domain: str) -> None:
    """Loads translations from `gettext`'s locale tree

    Locale tree is similar to system's ``/usr/share/locale``, like::

        {directory}/{lang}/LC_MESSAGES/{domain}.mo

    Three steps are required to have your app translated:

    1. Generate POT translation file::

        xgettext --language=Python --keyword=_:1,2 -d mydomain file1.py file2.html etc

    2. Merge against existing POT file::

        msgmerge old.po mydomain.po > new.po

    3. Compile::

        msgfmt mydomain.po -o {directory}/pt_BR/LC_MESSAGES/mydomain.mo
    """
    global _translations
    global _supported_locales
    global _use_gettext
    _translations = {}
    for lang in os.listdir(directory):
        if lang.startswith("."):
            continue  # skip .svn, etc
        if os.path.isfile(os.path.join(directory, lang)):
            continue
        try:
            os.stat(os.path.join(directory, lang, "LC_MESSAGES", domain + ".mo"))
            _translations[lang] = gettext.translation(
                domain, directory, languages=[lang]
            )
        except Exception as e:
            gen_log.error("Cannot load translation for '%s': %s", lang, str(e))
            continue
    _supported_locales = frozenset(list(_translations.keys()) + [_default_locale])
    _use_gettext = True
    gen_log.debug("Supported locales: %s", sorted(_supported_locales))