Comment 3 for bug 1663669

Well my patch is a bit of a sledgehammer, and there may be a more elegant way of handling this using the “parsing-error” signal of the Gtk.CssProvider class. We can have a callback that prints some debug info, then it should return to process the remainder of the file. We may still require the try/except clause, as it may still throw that exception on exiting the load_from_path function.