.SECONDARY appears to hang make 4.0 in specific Makefile

[Luke Goodsell]

$ make --version
GNU Make 4.0
Built for x86_64-pc-linux-gnu
Copyright (C) 1988-2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Hi,

Using the above version of make, I have a Makefile that runs immediately 
without .SECONDARY, but with .SECONDARY, it seems to hang during path finding. 
Output of `make -dns` shows make hanging after a 'Found an implicit rule' line.

Since the Makefile is quite complex, listing every target as .PRECIOUS or 
.INTERMEDIATE is not feasible. Yes, I do need to keep every intermediate file.

As the (sanitised) Makefile is a little big, I've placed it here: 
http://pastebin.com/FMv8BK3g

The output of `make -dns` with .SECONDARY: is here: http://pastebin.com/pTYhZXhL

I would greatly appreciate knowing what I am doing wrong.

Many thanks in advance,
Luke