Log level in boost unit test framework

I am using the boost unit test framework. I use the BOOST_TEST_MESSAGE function, and therefore I need to set the log level to at least message.

From reading the doc, I can do the following:

• I can add somehwere boost::unit_test::unit_test_log.set_threshold_level( boost::unit_test::log_messages); However, the doc indicates it to be generally considered bad practice.
• I can set the environment variable BOOST_TEST_LOG_LEVEL appropriately. This is a bad solution for me, as I will distribute my code, and I do not have a good way to constrain the user to set this environment variable appropriately in their bashrc.

Does anyone know a proper solution to this?