ScopedThread is undefined in 2.6.0 rc3 shell, it work fine with rc2 shell.
## RC2 shell root@rui-linux:/sys/kernel/mm/transparent_hugepage# /ssd2/mongodb-linux-x86_64-2.6.0-rc2/bin/mongo MongoDB shell version: 2.6.0-rc2 connecting to: test > t = new ScopedThread("test") 2014-04-03T17:12:51.009-0700 Error: first argument must be a function at src/mongo/shell/utils.js:113 > f = function() {return "";} function () {return "";} > t = new ScopedThread(f) { "init" : function init() { [native code] }, "start" : function start() { [native code] }, "join" : function join() { [native code] }, "returnData" : function returnData() { [native code] } } > ## RC3 shell root@rui-linux:/sys/kernel/mm/transparent_hugepage# /ssd2/mongodb-linux-x86_64-2.6.0-rc3/bin/mongo MongoDB shell version: 2.6.0-rc3 connecting to: test > f = function() {return "";} function () {return "";} > t = new ScopedThread(f) 2014-04-03T17:14:07.873-0700 ReferenceError: ScopedThread is not defined >