I am running Fedora Core 4 and have ant installed from an RPM.  I have so far
not needed to set ANT_HOME for anything, and given that the RPM splits data
over /usr/lib and /usr/share/java it's not clear what it should be set to.

When installing a gar the script stops because I don't have ANT_HOME set.  If I
try to set it to anything, I get class not found errors, however if I run the
java command which the script runs by hand, removing the -DANT_HOME= from the
command line, I no longer get an error from the java VM, but an error from 
org.globus.bootstrap.AntBootstrap.main(AntBootstrap.java:28) complaining that
the ANT_HOME system property is not set.

My final solution was to create a new 'ant_home' subdirectory and soft-link the
ant jars into a 'lib' subdirectory of that and set ANT_HOME to point to this
directory.

This is hardly an ideal situation.  Given that I can build Globus itself
without setting ANT_HOME, it seems strange that I need to set it to deploy a
gar file.