Patch #786737: Allow building in a tree of symlinks pointing to
a readonly source.
diff --git a/Makefile.pre.in b/Makefile.pre.in
index f9415aa..bafeb2b 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -61,7 +61,7 @@
 # Both CPPFLAGS and LDFLAGS need to contain the shell's value for setup.py to
 # be able to build extension modules using the directories specified in the
 # environment variables
-CPPFLAGS=	-I. -I$(srcdir)/Include @CPPFLAGS@
+CPPFLAGS=	-I. -IInclude -I$(srcdir)/Include @CPPFLAGS@
 LDFLAGS=	@LDFLAGS@
 LDLAST=		@LDLAST@
 SGI_ABI=	@SGI_ABI@
@@ -471,6 +471,7 @@
 
 
 $(GRAMMAR_H) $(GRAMMAR_C): $(PGEN) $(GRAMMAR_INPUT)
+		-@ mkdir Include
 		-$(PGEN) $(GRAMMAR_INPUT) $(GRAMMAR_H) $(GRAMMAR_C)
 
 $(PGEN):	$(PGENOBJS)