Fail To Build Doc

Fail to build doc , any one can help ??

./build api doc online

Building… : Yii Framework Class Reference

Type… : online

Version… : 1.1.15-dev

Source URL : https://github.com/yiisoft/yii/blob/master/framework

Building model…

PHP Error[2]: require_once(PHPUnit/Runner/Version.php): failed to open stream: No such file or directory

in file /root/yii/framework/test/CTestCase.php at line 11

#0 /root/yii/framework/test/CTestCase.php(11): require_once()

#1 /root/yii/framework/YiiBase.php(404): include()

#2 unknown(0): autoload()

#3 /root/yii/framework/test/CDbTestCase.php(40): spl_autoload_call()

#4 /root/yii/build/commands/api/ApiModel.php(35): require_once()

#5 /root/yii/build/commands/api/ApiModel.php(26): ApiModel->findClasses()

#6 /root/yii/build/commands/ApiCommand.php(247): ApiModel->build()

#7 /root/yii/build/commands/ApiCommand.php(124): ApiCommand->buildModel()

#8 /root/yii/framework/console/CConsoleCommandRunner.php(71): ApiCommand->run()

#9 /root/yii/framework/console/CConsoleApplication.php(92): CConsoleCommandRunner->run()

#10 /root/yii/framework/base/CApplication.php(180): CConsoleApplication->processRequest()

#11 /root/yii/framework/yiic.php(33): CConsoleApplication->run()

#12 /root/yii/build/build(17): require_once()