Nothing sets x_includes, so this breaks the test...

--- motif-2.3.8/ac_find_xft.m4	2017-03-27 23:24:31.000000000 +0100
+++ motif-2.3.8/ac_find_xft.m4	2025-07-04 03:40:04.844404583 +0100
@@ -134,8 +134,8 @@
 FINDXFT_HAVE_XRENDER="no"
 case "$have_x" in
 yes)
-	XRENDER_CFLAGS="-I$x_includes"
-	XRENDER_LIBS="-L$x_libraries -lXft -lXrender"
+	XRENDER_CFLAGS=""
+	XRENDER_LIBS="-lXft -lXrender"
 
 	saved_LIBS="$LIBS"
 	LIBS="$LIBS $XRENDER_LIBS"