HCatalog doesn't delete temp _SCRATCH dir when job failed

when we use HCatOutputFormat to write to an external partitioned table, a tmp dir (which starts with "_SCRATCH" ) will appear under table path if the job failed.

drwxr-xr-x - yun hdfs 0 2017-02-27 01:45 /tmp/hive/_SCRATCH0.31946356159329714
drwxr-xr-x - yun hdfs 0 2017-02-27 01:51 /tmp/hive/_SCRATCH0.31946356159329714/c1=1
drwxr-xr-x - yun hdfs 0 2017-02-27 00:57 /tmp/hive/c1=1
drwxr-xr-x - yun hdfs 0 2017-02-27 01:28 /tmp/hive/c1=1/c2=2
rw-rr- 3 yun hdfs 12 2017-02-27 00:57 /tmp/hive/c1=1/c2=2/part-r-00000
rw-rr- 3 yun hdfs 12 2017-02-27 01:28 /tmp/hive/c1=1/c2=2/part-r-00000_a_1