emacs-23.1.96: problem on GNU/Linux AMD64 (Red Hat 4.8)

[Nelson H. F. Beebe]

A build of emacs-23.1.96 on GNU/Linux AMD64 (Red Hat 4.8) with

        % set path=(/bin /usr/bin)
        % env LDFLAGS='-Wl,-rpath,/usr/local/lib64 -L/usr/local/lib64' 
./configure && make all check

failed like this:

        configure:15477: gcc -o conftest   -O2  -D_BSD_SOURCE   \
                -Wl,-rpath,/usr/local/lib64 -L/usr/local/lib64 
-Wl,-znocombreloc \
                -L/usr/X11R6/lib conftest.c -lungif  -lX11   >&5  
        /usr/bin/ld: skipping incompatible /usr/X11R6/lib/libX11.so when 
searching for -lX11
        /usr/bin/ld: skipping incompatible /usr/X11R6/lib/libX11.a when 
searching for -lX11
        /usr/bin/ld: cannot find -lX11
        collect2: ld returned 1 exit status
        configure:15484: $? = 1

On Red Hat and OpenSuSE AMD64 systems, the default world is 64-bit,
and libraries reside in /usr/local/lib64; the companion /usr/local/lib
holds only 32-bit libraries. Thus it is WRONG WRONG WRONG for
configure to be sticking in -L/usr/X11R6/lib, overriding the correct
settings supplied in LDFLAGS!  

The directory /usr/X11R6/lib has only 32-bit libraries, whereas
/usr/X11R6/lib64 has the needed 64-bit ones, and because that
directory is vendor supplied, it is already listed in the directories
known to /sbin/ldconfig, and thus need NOT be supplied.

I was able to get a successful build by putting /usr/local/bin at the
front of PATH; the config.log file then shows correct configure-time
tests like this:

        gcc -o conftest -O2 -D_BSD_SOURCE -Wl,-rpath,/usr/local/lib64 \
                -L/usr/local/lib64 -Wl,-znocombreloc  -L/usr/X11R6/lib64 \
                conftest.c -lX11

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- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- University of Utah                    FAX: +1 801 581 4148                  -
- Department of Mathematics, 110 LCB    Internet e-mail: address@hidden  -
- 155 S 1400 E RM 233                       address@hidden  address@hidden -
- Salt Lake City, UT 84112-0090, USA    URL: http://www.math.utah.edu/~beebe/ -
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