It looks like you have a problem with gtk2.  It may be that the
x11/gtk2/buildlink3.mk file is out of sync with what you have
installed.  So things to try:

A) update all of pkgsrc, and do 'make update' in x11/gtk2.
Then try again.

B) Use pkg_comp, and build a fresh set of everything from the same
pkgsrc tree.

C) in chat/gaim, do 'make configure, and look where gtk/gtk.h is in
the buildlink include tree, and the real tree.  look at gtkspell.c and
see if it's including things correctly.  I see

-I/usr/pkg/include/gtk-2

on the libtool compile line, and I think this is translated into (your
command output was line-wrapped-mangled):

-I/usr/pkgsrc/textproc/g
tkspell/work/.buildlink/lib/gtk-2.0/include

and in there should be a gtk/ dir with a symlink to
/usr/pkg/include/gtk-2.0/gtk/gtk.h.  It may be that this isn't getting
buildlinked in.  To get past the build, you can just symlink it in by
hand after 'make buildlink' 

On my system (2.0_RC4 with packages built around 10/12), gtkspell
buildlink bits look ok, and built ok.  But I have had gtk buildink
trouble in the past.


In general this is a pkgsrc issue - the buildlink3.mk file somehow
needs to match the installed package, not the source, since it's the
installed version that is compiled against.  Perhaps they need to go
in /var/db/pkg?  But, I think the real answer is that buildlink3 files
have required versions, and on an incompatible update the required
version needs to be bumped so the API/ABI of the installed version
matches what the buildlink3 file expects.  Thus, I suspect there was
simply a bug at some time in the past.

-- 
        Greg Troxel <gdt@ir.bbn.com>