如何在 sonarqube 5.0 中使用 git 作为 scm provider

官方说明：
http://docs.sonarqube.org/display/SONAR/SCM+support
按照官方的说法部署，但是是执行 sonar-runner 有报错信息如下，提示说获取不到人员的信息。
总觉得还是需要在什么地方配置用户登录信息，类似文中使用 svn 作为scm 一样。

08:46:33.723 INFO - Sensor SCM Sensor...
08:46:33.897 INFO - SCM provider for this project is: git
08:46:33.898 INFO - Retrieve SCM blame information...
08:46:33.915 INFO - 632 files to be analyzed
08:46:34.377 INFO - Author: PersonIdent[Not Committed Yet, , Tue Feb 3 08:46:34 2015 +0000]
08:46:34.379 INFO - Source commit: null
08:46:34.377 INFO - Author: PersonIdent[Not Committed Yet, , Tue Feb 3 08:46:34 2015 +0000]
08:46:34.924 INFO - Source commit: null
INFO: ------------------------------------------------------------------------
INFO: EXECUTION FAILURE
INFO: ------------------------------------------------------------------------
Total time: 1:01.699s
08:46:35.891 INFO - Author: PersonIdent[Not Committed Yet, , Tue Feb 3 08:46:35 2015 +0000]
08:46:34.930 INFO - Author: PersonIdent[Not Committed Yet, , Tue Feb 3 08:46:34 2015 +0000]
08:46:35.930 INFO - Source commit: null
Final Memory: 27M/318M
INFO: ------------------------------------------------------------------------
ERROR: Error during Sonar runner execution
ERROR: Unable to execute Sonar
ERROR: Caused by: Unable to blame file

google 也没有找到相关的。。