I was seeing various issues with parallel make, mainly due to to what was likely 
partially installed headers. If you change into the source directory and
"NOISY=1 make  ../obj/apt-pkg/sourcelist.opic" in apt-pkg, you'll see it 
doesn't have any dependencies on the headers being installed. This patch
fixes that so things build correctly.

RP 2012/3/19

Upstream-Status: Pending

Index: apt-0.9.9.4/buildlib/library.mak
===================================================================
--- apt-0.9.9.4.orig/buildlib/library.mak	2013-07-31 15:45:07.320440575 +0300
+++ apt-0.9.9.4/buildlib/library.mak	2013-07-31 15:46:49.440440561 +0300
@@ -61,7 +61,7 @@
 
 # Compilation rules
 vpath %.cc $(SUBDIRS)
-$(OBJ)/%.opic: %.cc $(LIBRARYDEPENDS)
+$(OBJ)/%.opic: %.cc $(LIBRARYDEPENDS) $($(LOCAL)-HEADERS)
 	echo Compiling $< to $@
 	$(CXX) -c $(INLINEDEPFLAG) $(CPPFLAGS) $(CXXFLAGS) $(PICFLAGS) -o $@ $<
 	$(DoDep)