parallel build failure(s)

[Graham Gower]

Hi,

I'm using openembedded to cross build gnutls 2.10.2 and have seen a
build failure which looks like its caused by missing dependencies
in guile/src/Makefile.am. I am building with make -j 12.

My failure:
http://tinderbox.openembedded.net/public/logs/task/10751151.txt
Another, similar failure:
http://tinderbox.openembedded.net/public/logs/task/7589267.txt

Its clear to me that the failures are due to the header file not
being fully created before the guile-snarf process is invoked.

I suspect something like the below patch may be the solution, but
as I'm unable to easily reproduce the failure, I cannot reliably
test it.

-Graham

diff --git a/guile/src/Makefile.am.orig b/guile/src/Makefile.am
index e8e81b1..2ee1297 100644
--- a/guile/src/Makefile.am.orig
+++ b/guile/src/Makefile.am
@@ -122,7 +122,7 @@ extra-smob-types.i.c: $(srcdir)/make-smob-types.scm
 snarfcppopts = $(DEFS) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) \
 	       $(CFLAGS) $(AM_CFLAGS) $(GUILE_CFLAGS)
 
-.c.x:
+.c.x: $(BUILT_SOURCES)
 	$(guile_snarf) -o $@ $< $(snarfcppopts)
 
 # Target used by doc/Makefile, to create all built sources necessary