devel/gtexinfo/Makefile has:

PKGSRC_INFOPATH=        ${PREFIX}/info:${X11BASE}/info:${LOCALBASE}/info
MAKE_ENV+=              PKGSRC_INFOPATH="${PKGSRC_INFOPATH}"

And patch-ac basically does:

+#  define DEFAULT_INFOPATH PKGSRC_INFOPATH ":"
"/usr/local/info:/usr/info:/usr/local/lib/info:/usr/lib/info:/usr/local/gnu/info:/usr/local/gnu/lib/info:/usr/gnu/info:/usr/gnu/lib/info:/opt/gnu/info:/usr/share/info:/usr/share/lib/info:/usr/local/share/info:/usr/local/share/lib/info:/usr/gnu/lib/emacs/info:/usr/local/gnu/lib/emacs/info:/usr/local/lib/emacs/info:/usr/local/emacs/info:."

I seems like ${PREFIX}/info:${X11BASE}/info:${LOCALBASE}/info is
redundant, because PREFIX is probably not needed (because would be same as
LOCALBASE).

Also, if for some rare case where INFO_DIR is setup by someone to
something not in above list, then the installed info tool wouldn't see the
info documents.

Is this okay?

@@ -17,7 +17,7 @@
 USE_PKGLOCALEDIR=	yes
 GNU_CONFIGURE=		yes

-PKGSRC_INFOPATH=	${PREFIX}/info:${X11BASE}/info:${LOCALBASE}/info
+PKGSRC_INFOPATH=	${PREFIX}/${INFO_DIR}:${X11BASE}/info:${LOCALBASE}/info
 MAKE_ENV+=		PKGSRC_INFOPATH="${PKGSRC_INFOPATH}"

 INFO_FILES=		info-stnd.info info.info texinfo

   Jeremy C. Reed
   http://www.reedmedia.net/

p.s. There may still be a problem with using NetBSD's native /usr/bin/info
because its DEFAULT_INFOPATH is only
\"/usr/pkg/info:/usr/X11R6/info:/usr/X11/info
:/usr/local/info:/usr/share/info:/usr/info\"

p.p.s. I just noticed that my Makefile has:

-CATEGORIES=		devel
+CATEGORIES=		sysutils

gtexinfo seems like it should be in sysutils category.

-COMMENT=		GNU info file manipulation utilities
+COMMENT=		GNU info documentation utilities

Maybe should mention "documentation" in COMMENT?