error installing GATK

[dkrtndhkd]

hi, i have a problem installing GATK.

procedure:

1. go to GATK site and install prerequisite program.

2. go to the following site:

http://www.broadinstitute.org/gsa/wi...ading_the_GATK

and go and do straight step#2.
1 Getting a Pre-Built Version
1.1 Within the Broad Institute
1.2 Outside the Broad Institute
-> 2 Building the GATK from source <-
3 Checking out a specific version of the GATK source
3.1 Using a version number to check out a specific version of the GATK source
3.2 Using a commit ID to check out a specific version of the GATK source
4 Signing up for email notifications whenever there's a new GATK release
5 Supplemental Files

As i know, step#1 is downloading the GATK program and installing it
and step#2 is installing GATK program throught git hub.
so, if i choose step#2, i don't need step#1 process right??

with this strategy, i installed GATK, there was an error message at the end:
(after input command line : cd destination_directory/ant)

BUILD FAILED
/home/sheun/gatk/build.xml:323: Compile failed; see the compiler error output for details.

what am i doing wrong?