Description
Although MAHOUT-757 moved towards standard option naming, it uses different APIs for option parsing than other jobs.
On my system, it died reliably with null pointer error. Reported in mail here, but not reconfirmed by anyone else yet: http://permalink.gmane.org/gmane.comp.apache.mahout.user/9659
Example:
TellyClub:bin danbri$ ./mahout rowid --help
MAHOUT_LOCAL is set, so we don't add HADOOP_CONF_DIR to classpath.
MAHOUT_LOCAL is set, running locally
[skipping some hopefully unrelated SLF4J errors re same thing on classpath twice]
Exception in thread "main" java.lang.NullPointerException
at org.apache.hadoop.fs.Path.<init>(Path.java:61)
at org.apache.hadoop.fs.Path.<init>(Path.java:50)
at org.apache.mahout.utils.vectors.RowIdJob.run(RowIdJob.java:49)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79)
at org.apache.mahout.utils.vectors.RowIdJob.main(RowIdJob.java:89)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:68)
at org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:139)
at org.apache.mahout.driver.MahoutDriver.main(MahoutDriver.java:188)