[ 
https://issues.apache.org/jira/browse/HADOOP-10018?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13786510#comment-13786510
 ] 

Haohui Mai commented on HADOOP-10018:
-------------------------------------

I believe that the Shell class will need a valid directory in order to ensure 
that getcwd() succeeds. That's the reason why hadoop.home.dir needs to be set 
to a valid path.

it might not be a good idea to depend on java properties or environment 
variables. For example, using the environment variable HADOOP_HOME causes this 
bug. Similar issues might arise for properties like user.home -- I'm unfamiliar 
with the partsof JDK specifications that specify that user.home has to be a 
valid path (in fact it might not be, due to bugs in JDK: 
http://stackoverflow.com/questions/2134338/java-user-home-is-being-set-to-userprofile-and-not-being-resolved).

Notice that simply setting it to "/" won't work either due to Windows 
compatibility.

I agree that setting to a temporary directory is imperfect, but compared to 
alternative approaches it seems this one is slightly more robust and more 
platform neutral.

> TestUserGroupInformation throws NPE when HADOOP_HOME is not set
> ---------------------------------------------------------------
>
>                 Key: HADOOP-10018
>                 URL: https://issues.apache.org/jira/browse/HADOOP-10018
>             Project: Hadoop Common
>          Issue Type: Bug
>            Reporter: Haohui Mai
>            Assignee: Haohui Mai
>            Priority: Minor
>         Attachments: HADOOP-10018.000.patch
>
>
> TestUserGroupInformation throws NPE in System.setProperty() when HADOOP_HOME 
> is not set.



--
This message was sent by Atlassian JIRA
(v6.1#6144)

Reply via email to