def METHOD_NAME(self, module_name):
    self.start_msg('Ruby module %s' % module_name)
    try:
        self.cmd_and_log(self.env.RUBY + ['-e', 'require \'%s\';puts 1' % module_name])
    except Errors.WafError:
        self.end_msg(False)
        self.fatal('Could not find the ruby module %r' % module_name)
    self.end_msg(True)