JDBC build fails

Can someone please fix this? Building JDBC staffs in current has been
broken for a while(7.2.x is ok). Maybe current JDBC build process
requires more recent version of ant than I have, I don't know. But if
so, that should be stated somewhere in the docs explicitly, I think.

/usr/bin/ant -buildfile ./build.xml all \ -Dmajor=7 -Dminor=3 -Dfullversion=7.3devel -Ddef_pgport=5432
-Denable_debug=yes
Buildfile: ./build.xml

all:

prepare:

BUILD FAILED

/usr/local/src/pgsql/current/pgsql/src/interfaces/jdbc/./build.xml:155: Could not create task of type: condition.
Commonsolutions are to use taskdef to declare your task, or, if this is an optional task, to put the optional.jar in
thelib directory of your ant installation (ANT_HOME).
 

FYI, my build tools are:

Java: 1.3.0
Ant: 1.3