rem: alert(err); 
add: dump(err); 
context: 		d.addErrback(function (err) {         if (err instanceof CancelledError) {           return;         }        alert(err);      });
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/10234/a3a9a2c311afc9d76e4e6bfc036e5897fa988bc1/common.js/buggy/testing/extensions/community/chrome/content/common.js