I found where the patch made libstroke link explicitly with -ltcl83
and changed it in the Makefile.in to -ltcl84.

This got me a little further until it failed as follows:

[...]
 gcc -DHAVE_CONFIG_H -I. -I.. -I../include -I/Volumes/NetBSD/pkgsrc/devel/libstroke/work/.x11-buildlink/include -no-cpp-precomp -I/Volumes/NetBSD/pkgsrc/devel/libstroke/work/.buildlink/include -O2 -c tcl.c -o tcl.o >/dev/null 2>&1
/bin/sh ../libtool --mode=link gcc  -O2 -I/usr/pkg/include -L/usr/pkg/lib -L/usr/X11R6/lib -o libstroke_tcl.la -rpath /usr/pkg/lib -ltcl84 -version-info 0:3:0 tcl.lo stroke.lo
gcc -dynamiclib -flat_namespace -undefined suppress -o .libs/libstroke_tcl.0.3.dylib  .libs/tcl.o .libs/stroke.o  -L/Volumes/NetBSD/pkgsrc/devel/libstroke/work/.buildlink/lib -L/Volumes/NetBSD/pkgsrc/devel/libstroke/work/.x11-buildlink/lib /Volumes/NetBSD/pkgsrc/devel/libstroke/work/.buildlink/lib/libtcl84.dylib -install_name  /usr/pkg/lib/libstroke_tcl.0.dylib -compatibility_version 1 -current_version 1.3
ld: multiple definitions of symbol _point
.libs/tcl.o definition of _point in section (__DATA,__common)
.libs/stroke.o definition of _point in section (__DATA,__common)
/usr/bin/libtool: internal link edit command failed
*** Error code 1

Stop.
bmake: stopped in /Volumes/NetBSD/pkgsrc/devel/libstroke/work/libstroke-0.3/libstroke
[...]

Perhaps this is why libstroke appears to have a hard dependency on tcl83?
Unless I missed something tcl83/tk83 have not (yet?) been patched to build
on MacOS X the way tcl/tk (8.4.6) have.

Thanks.

-- 
John D. Baker, KN5UKS                    NetBSD     Darwin/MacOS X
jdbaker(at)mylinuxisp(dot)com                 OpenBSD            FreeBSD
BSD -- It just sits there and _works_!