On 13.1 it should work without a problem…

/bin/sh ../../libtool –silent –mode=link gcc -pedantic -W -Wall -Werror -Wno-long-long -O2 -march=i486 -mtune=i686 -pipe -fno-strict-aliasing -fno-common -fexceptions -ggdb3 -D_FORTIFY_SOURCE=2 -w -L/usr/local/lib -pipe -fno-strict-aliasing -fno-common -fexceptions -ggdb3 -D_FORTIFY_SOURCE=2 -w -o libbu_nil.la argv.lo avs.lo backtrace.lo badmagic.lo basename.lo bitv.lo bomb.lo brlcad_path.lo cmd.lo cmdhist.lo cmdhist_obj.lo color.lo convert.lo crashreport.lo dirent.lo dirname.lo endian.lo fchmod.lo fgets.lo fnmatch.lo fopen_uniq.lo getopt.lo globals.lo hash.lo hist.lo hook.lo htond.lo htonf.lo image.lo interrupt.lo ispar.lo kill.lo lex.lo linebuf.lo list.lo log.lo magic.lo malloc.lo mappedfile.lo mread.lo mro.lo observer.lo parallel.lo parse.lo printb.lo process.lo ptbl.lo quote.lo rb_create.lo rb_delete.lo rb_diag.lo rb_extreme.lo rb_free.lo rb_insert.lo rb_order_stats.lo rb_rotate.lo rb_search.lo rb_walk.lo semaphore.lo simd.lo stat.lo str.lo tcl.lo temp.lo units.lo vers.lo vfont.lo vlb.lo vls.lo whereis.lo which.lo xdr.lo
/bin/sh ../../libtool –silent –mode=link gcc -pedantic -W -Wall -Werror -Wno-long-long -O2 -march=i486 -mtune=i686 -pipe -fno-strict-aliasing -fno-common -fexceptions -ggdb3 -D_FORTIFY_SOURCE=2 -w -L/usr/local/lib -pipe -fno-strict-aliasing -fno-common -fexceptions -ggdb3 -D_FORTIFY_SOURCE=2 -w -o libbu.la -rpath /opt/brlcad/lib -version-info 19:1 -no-undefined libbu_nil.la -ltcl8.5 -lpng -lm -lc -lpthread
gcc -DHAVE_CONFIG_H -I. -I. -I../../include -DPREFIX=\”/opt/brlcad\” -I/usr/local/include -DBRLCADBUILD=1 -I../../include -I../../src/other/openNURBS -pedantic -W -Wall -Werror -Wno-long-long -O2 -march=i486 -mtune=i686 -pipe -fno-strict-aliasing -fno-common -fexceptions -ggdb3 -D_FORTIFY_SOURCE=2 -w -c `test -f ‘htester.c’ || echo ‘./’`htester.c
/bin/sh ../../libtool –silent –mode=link gcc -pedantic -W -Wall -Werror -Wno-long-long -O2 -march=i486 -mtune=i686 -pipe -fno-strict-aliasing -fno-common -fexceptions -ggdb3 -D_FORTIFY_SOURCE=2 -w -L/usr/local/lib -pipe -fno-strict-aliasing -fno-common -fexceptions -ggdb3 -D_FORTIFY_SOURCE=2 -w -o htester htester.o libbu.la -ltcl8.5 -lpng -lm -lc -lpthread
/usr/lib/gcc/i486-slackware-linux/4.2.4/../../../../i486-slackware-linux/bin/ld: cannot find -lz
collect2: ld returned 1 exit status
make[2]: *** [htester] Error 1
make[2]: Leaving directory `/tmp/SBo/brlcad-7.16.10/src/libbu’
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/tmp/SBo/brlcad-7.16.10/src’
make: *** [all-recursive] Error 1
root@amd-3c:~/brlcad#