./configure error - readline library not found

Howdy.

I looked around for an answer to this, but I was unable to find one that
seemed to match my situation.  (Incidentally, now I cannot get
archives.postgresql.org to respond to my search query...)

I'm trying to build 7.3.4 on Libranet2.8.1 (debian).  I've built
PostgreSQL many times in the past on stock RedHat distros and had no
problem.

When running ./configure, I keep getting stuck when it checks for readline.

checking for readline... no
configure: error: readline library not found
If you have readline already installed, see config.log ...

I've looked in config.log and I don't really get any more explanation
about why it couldn't find the library.

I've tried different --with-libs= paths and had no luck.

I have libreadline4.3-4 installed, and I think the relevant library file
is /lib/libreadline.so.4

Any suggestions?

Thanks much.

Michael Teter