Download and install the libgcj SRPM
rpm -i libgcj-2.96-29.src.rpm
Compile the package
cd /usr/src/redhat/SPECS
rpm -bc libgcj.spec
Link liberco
cd ${ERCO_HOME}/lib/liberco
ln -s /usr/src/redhat/BUILD/libgcj/obj-i386-redhat-linux/i386-redhat-linux/libjava/ .
ln -s /usr/src/redhat/BUILD/libgcj/obj-i386-redhat-linux/i386-redhat-linux/libffi/ .
make