使用 -X 选项（调试）启动 maven 并检查输出的开头。应该有这样的东西：

...
[INFO] Error stacktraces are turned on.
[DEBUG] Reading global settings from c:\....\apache-maven-3.0.3\conf\settings.xml
[DEBUG] Reading user settings from c:\....\.m2\settings.xml
[DEBUG] Using local repository at C:\....\repository
...

（原来的目录名被我删除了）