7.4RC2: CLASSPATH set breaks configure?

If I have CLASSPATH set to pick up junit:

CLASSPATH=/home/ler/java/classes/junit.jar
export CLASSPATH

and then run configure:
$ cat ler.conf
CC=cc CXX=CC ./configure --prefix=/usr/local/pgsql --enable-syslog \
--with-CXX --enable-multibyte --enable-cassert \
--with-includes=/usr/local/include --with-libs=/usr/local/lib \
--with-tcl --with-tclconfig=/usr/local/lib \
--with-tkconfig=/usr/local/lib --enable-locale \
--enable-thread-safety --with-java
$ sh ler.conf

configure dies:
configure: creating ./config.status
./configure: line 18048: cat: not found
config.status: creating GNUmakefile

If I unset CLASSPATH, all works well.

Anyone have any ideas?

(Is my JAVA installation at fault, maybe?, It's beta).

--
Larry Rosenman http://www.lerctr.org/~ler
Phone: +1 972-414-9812 E-Mail: ler(at)lerctr(dot)org
US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749