protected function deleteTmpDir() {
		// Cleanup temporary directory, if any
		if ( ! empty( $this->tmpDir ) ) {
			\Pressbooks\Utility\rmrdir( $this->tmpDir );
		}
		// Cleanup deprecated junk, if any
		$exports_folder = untrailingslashit( pathinfo( $this->outputPath, PATHINFO_DIRNAME ) );
		if ( ! empty( $exports_folder ) ) {
			\Pressbooks\Utility\rmrdir( "{$exports_folder}/META-INF" );
			\Pressbooks\Utility\rmrdir( "{$exports_folder}/media" );
		}
	}