SIMPLE DEBUG-APPROACH FOR SASS

In bootstrap.php:

$d = new Kwf_Assets_Dependency_File_Scss('web/themes/Theme/Master.scss');
echo ($d->getContentsPacked('de')->getFileContents());
exit;

and then comment out most scss in Master.scss and only let one simple selector in use to start debugging:

To view sass variables use:

debug: $val;

where $val can be every variable.