Hi Dan,
I'm not sure but I think it might be better in a renderers directory and called core_renderer.php instead, kind of in the same what that Bootstrapbase has it's renderers. Then the file renderers.php just takes the call from Moodle and pulls in renderers/core_renderer.php with a require_once like this.
So this is the content of the renderers.php
<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Renderers for My Theme
*
* @package theme_mytheme
* @copyright 2015
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
require_once('renderers/core_renderer.php');
And add the highlighted line to your new renderers/core_renderer.php
require_once($CFG->dirroot.'/blocks/course_overview/locallib.php');
include_once ($CFG->dirroot. '/theme/bootstrapbase/renderers.php');
class theme_mytheme_core_renderer extends theme_bootstrapbase_core_renderer {
Which is the correct way to do things.
Cheers
Mary