Hello, I need to build hadoop in Linux as I need to make some small changes in the code, but I don't know what is the simplest way to build hadoop. I googled it and so far I only found two places that tell how to build hadoop. One is http://bigdata.wordpress.com/2010/05/27/hadoop-cookbook-3-how-to-build-your-own-hadoop-distribution/. I downloaded apache forrest, and do as it ant -Djava5.home=/usr/lib/jvm/java-1.5.0-gcj-4.4/ -Dforrest.home=/home/zhengda/apache-forrest-0.8 compile-core tar and get an error: [exec] BUILD FAILED [exec] /home/zhengda/apache-forrest-0.8/main/targets/validate.xml:158: java.lang.NullPointerException What does this error mean? it seems apache forrest is used to create hadoop document and I just want to rebuild hadoop java code. Is there a way for me to just rebuild java code? I ran "ant", it seems to work successfully, but I don't know if it really compiled the code.
the other place I found is to show how to build hadoop with eclipse. I use macbook and I have to ssh to linux boxes to work on hadoop, so it's not a very good option even if it can really work. Best, Da
