readline.h / history.h error at ./configure

Hi all,

I'm trying to get 'readline' and 'history' support for the PostgreSQL
shell.

Working in psql without all the bash features (like auto completion
etc.) is very nasty.

I receive the following error by configuring PostgreSQL:

".....
checking for netinet/tcp.h... yes
checking whether string.h and strings.h may both be included...
(cached) yes
checking for readline/readline.h... (cached) no
checking for readline.h... (cached) no
checking for readline/history.h... (cached) no
checking for history.h... (cached) no
....."

The two files readline.h and history.h are in ' /usr/include/readline/
' and softlinked inside ' /usr/include ' as well.
The netinet/tcp.h lives in ' /usr/include/ ' too and the configure
script likes it.

Where is the error?
Is there a central index for all header files, where tcp.h is included
and readline.h is not?
By the way: What means "(cached)"?

Or is there a bug in the PostgreSQL 7.2.3 configure script ?

Many thanks for any suggestions!

Regards,
Stefan Stern