just edit your /etc/ld.so.conf file and include the needed $PATH variables
I don't think ldconfig and /etc/ld.so.conf have anything to do with the $PATH or any other environment variable. When you run ldconfig it goes through the entries in /etc/ld.so.conf (and /etc/ld.so.conf.d/) and uses those to update the /etc/ld.so.cache file, which in turn is used by the ld.so run-time linker.
Environment variables are set in /etc/profile, /etc/bashrc, ~/.bash_profile, ~/.bashrc and so on and although the ld.so linker will pay attention to the LD_LIBRARY_PATH environment variable, if its set, this has nothing to do with ldconfig or /etc/ld.so.conf. See man ldconfig man ld.so
/etc/ld.so.conf is only for directories which have libraries, the linking system can't do anything with include files
umgambit:I solved this by:
./configure --x-includes='/usr/X11/include' --x-libraries='/usr/X11/lib'
which are the usual locations of these dependencies.
Well on my Mandriva system, which claims to be FHS and LSB compliant, its /usr/X11R6/include/ for the includes and /usr/X11R6/lib/ for the libs. Assuming those are the correct locations its probably just that the configure script was written before the FHS standard or something like that.
configure: error: We need a working libXext to proceed. Since configure
can't find it itself, we stop here assuming that make wouldn't find
I have no idea of how to correct this.
Furthermore, i have the files libXext.so.6 and libXext.so.6.4
in /usr/X11R6/lib ....!
You're pointing the configure script to /usr/X11/lib - why are you pointing it there if you're X library files are in /usr/X11R6/lib? What's actually in /usr/X11/lib?