title: When libhdfs hdfsRename will return -1
body: <p>I use libhdfs in my c++ program, when I use hdfsRename to mv a file from old path to new path. the new path is not exist, and the old path is exist.<br>
  But when I run the program, I get an error, the function hdfsRename just return -1 without any tips or exception.<br>
  I use gdb to debug the program, but I can't step into the jvm thread to know what happened.<br>
  So anyone can tell me, When the hdfsRename will return -1, and is there a way to debug into jvm?</p>