swi-prolog fails because of ncurses (missing required architecture x86_64 in file)

[herbert.fischer@…]

Build of swi-prolog fails because ncurses (build at the same time) does not support x86_64.

_opt_local_var_macports_sources_rsync.macports.org_release_ports_lang_swi-prolog/work/destroot/opt/local/lib/swipl-5.6.63/doc/Manual; fi; \
		  for f in ../man/Manual/*.html ../man/Manual/*.gif; do \
		    /usr/bin/install -c -m 644 $f /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_lang_swi-prolog/work/destroot/opt/local/lib/swipl-5.6.63/doc/Manual; \
		  done; \
		fi
cd packages && /usr/bin/make install
for p in clib cpp odbc table xpce sgml sgml/RDF semweb http chr clpqr nlp ssl pldoc plunit jpl zlib; do \
	    if [ -r $p/Makefile ]; then ( cd $p && make install ) || exit 1; fi; \
        done
../plld.sh -O2 -fno-strict-aliasing -Wall -fpic -I. -Imaildrop/rfc2045 -Imaildrop/rfc822 -DHAVE_CONFIG_H   -c -o random.o random.c
../plld.sh -shared -o random.dylib random.o
ld: in /usr/lib/libncurses.5.dylib, missing required architecture x86_64 in file
collect2: ld returned 1 exit status
/usr/bin/gcc-4.2 returned code 256
*** /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_lang_swi-prolog/work/pl-5.6.63/src/../src/plld exit status 1
make[2]: *** [random.dylib] Error 1
make[1]: *** [install] Error 1
make: *** [install-world] Error 2

Error: Status 1 encountered during processing.

[herbert.fischer@…]

Forgot to mention. It's on Snow Leopard.