static function display( PLUGError $Err ){
		$html = ini_get('html_errors');
		if( $html ){
			$s = '<div class="error"><strong>%s:</strong> %s. in <strong>%s</strong> on line <strong>%u</strong></div>';
		}
		else {
			$s = "\n%s: %s. in %s on line %u";
		}
		$args = array ( 
			$s,
			$Err->getTypeString(),
			$Err->getMessage(), 
			$Err->getFile(),
			$Err->getLine()
		);
		// add trace in dev mode
		if( ! PLUG::is_compiled() ){
			$args[0] .= $html ? "\n<pre>%s</pre>" : "\n%s";
			$args[] = $Err->getTraceAsString();
		}
		return call_user_func_array( 'sprintf', $args );
	}