gem install gettext-haml

If you use rxgettext, require gettext-haml by --require:

rxgettext --require gettext-haml ...

If you use gettext as library, require gettext-haml in your Ruby script:

require "gettext-haml"

LGPLv3 or later. See doc/text/lgpl-3.0.txt or https://www.gnu.org/licenses/lgpl-3.0.txt for details.