exception 'LogicException' with message 'Render context is empty, because render() was called outside of a [error] renderRoot()

The full error and stack trace are reproduced when trying to run "drush dmu-anaylze MODULENAME". Luckily the fix is quite simple - replace the render() function with the drupal_render_root() function OR (As I have done here), go straight to the renderer service (as this lovely helper function will be removed at some point in the future).