chat/libpurple's buildlink3.mk should pull in the dbus buildlink3.mk's
when its options includes dbus.  Patch below.  This could be
compacted to only include dbus-glib/buildlink3.mk as it pulls in
dbus/buildlink3.mk, but I'm not sure which is considered more
desirable.

I'm not sure if the other package options should cause their
corresponding buildlink3.mk's to be included too?  gnutls seems
safe (the libpurple*.so don't reference any gnutls libraries).

(libpurple's maintainer is set to pkgsrc-users.)

diff -w -b -u -r1.3 buildlink3.mk
--- buildlink3.mk       13 Aug 2007 12:42:06 -0000      1.3
+++ buildlink3.mk       1 Oct 2007 19:06:23 -0000
@@ -16,4 +16,9 @@
 BUILDLINK_PKGSRCDIR.libpurple?=        ../../chat/libpurple
 .endif # LIBPURPLE_BUILDLINK3_MK
 
+.if !empty(PKG_OPTIONS.libpurple:Mdbus)
+.  include "../../sysutils/dbus/buildlink3.mk"
+.  include "../../sysutils/dbus-glib/buildlink3.mk"
+.endif
+
 BUILDLINK_DEPTH:=              ${BUILDLINK_DEPTH:S/+$//}

-- 
  Brian de Alwis | Software Practices Lab | UBC | http://www.cs.ubc.ca/~bsd/
      "Amusement to an observing mind is study." - Benjamin Disraeli