postgresql-8.0.1/Solaris 9/Readline-5.1

Hello List,
I currently recompiled postgresql-8.0.1 for Solaris 9, with the
--enable-thread-safety, to appease the install of Slony-I which worked
wonderfully
I used the following configure line:

./configure --enable-thread-safety --without-readline

and the remainder of the defaults were fine.

I then, make all'd and make install'd.  Slony-I was a successful build
as well after pointing to the new library and include folders.

The issue I have is, that I actually want readline compiled in.  This
feature allows my command buffer to exist.

My 2nd round of compiling has a more lengthy ./configure line... no
matter what I use and include, I can't get the configure script to work,
UNLESS I specify --without-readline

I have the prebuilt 5.1 of readline from www.sunfreeware.com installed.
I know where the lib and include directories are located and I'm
including those with the correct command line options.  I know,
especially because I can get successful configures --with-perl and a few
other options, where I also need to specify the lib and include folders
for the features.

Has anybody seen an issue with compiling "readline" into
postgresql-8.0.1?  The pre-built postgresql-8.0.1 from sunfreeware works
WITH readline, but doesn't have --enable-thread-safety.

Anyway, thanks in advance.  By the way, Slony-I is really cool!