Readline, Postgresql and Solaris

I've been trying to install readline in Solaris so that Postgresql
detects readline during ./configure. However, doing a ./configure and
make install to install readline from source in Solaris just isn't
enough to get Postgresql to detect readline during its ./configure. I
have been able to get postgresql to detect readline if I use pkg-get to
install readline. However, I need to figure out how to do this
manually/without pkg-get. Is there someone who knows what I need to do?

Thanks in advance,

Josh