ERROR org.apache.pig.tools.grunt.Grunt - ERROR 2997: Encountered IOException. File or directory null

pig运行时报错：

grunt>ls

2015-11-11 20:24:39,159 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 2997: Encountered IOException. File or directory null does not exist.

Details at logfile: /silence/pig0.13/pig_1447244658222.log

正确的做法：

grunt> ls /
hdfs://localhost:9000/hbase    <dir>
hdfs://localhost:9000/home    <dir>
hdfs://localhost:9000/input    <dir>
hdfs://localhost:9000/newFoler1    <dir>
hdfs://localhost:9000/test1<r 3>    12
hdfs://localhost:9000/test2<r 3>    12
hdfs://localhost:9000/tmp    <dir>