--- a/Makefile.in	Thu May 18 23:38:30 2017 +0800
+++ b/Makefile.in	Thu May 18 23:45:10 2017 +0800
@@ -24,6 +24,10 @@
 LIBTOM_LIBS=$(STATIC_LTC) $(STATIC_LTM) 
 endif
 
+ifneq ($(wildcard localoptions.h),)
+CFLAGS+=-DLOCALOPTIONS_H_EXISTS
+endif
+
 COMMONOBJS=dbutil.o buffer.o dbhelpers.o \
 		dss.o bignum.o \
 		signkey.o rsa.o dbrandom.o \
@@ -76,6 +80,8 @@
 sbindir=@sbindir@
 mandir=@mandir@
 
+.DELETE_ON_ERROR:
+
 CC=@CC@
 AR=@AR@
 RANLIB=@RANLIB@
@@ -155,7 +161,6 @@
 
 inst_dropbearmulti: $(addprefix insmulti, $(PROGRAMS)) 
 
-
 # for some reason the rule further down doesn't like $($@objs) as a prereq.
 dropbear: $(dropbearobjs)
 dbclient: $(dbclientobjs)
@@ -195,18 +200,18 @@
 	-ln -s dropbearmulti$(EXEEXT) $*$(EXEEXT)
 
 $(STATIC_LTC): options.h
-	cd libtomcrypt && $(MAKE)
+	$(MAKE) -C libtomcrypt
 
 $(STATIC_LTM): options.h
-	cd libtommath && $(MAKE)
+	$(MAKE) -C libtommath
 
 .PHONY : clean sizes thisclean distclean tidy ltc-clean ltm-clean
 
 ltc-clean:
-	cd libtomcrypt && $(MAKE) clean
+	$(MAKE) -C libtomcrypt clean
 
 ltm-clean:
-	cd libtommath && $(MAKE) clean
+	$(MAKE) -C libtommath clean
 
 sizes: dropbear
 	objdump -t dropbear|grep ".text"|cut -d "." -f 2|sort -rn
@@ -224,6 +229,14 @@
 tidy:
 	-rm -f *~ *.gcov */*~
 
+# default_options.h is stored in version control, could not find a workaround
+# for parallel "make -j" and dependency rules.
+default_options.h: default_options.h.in 
+	echo "# > > > Generated from $^, edit that file instead !" > [email protected]
+	echo >> [email protected]
+	$(srcdir)/ifndef_wrapper.sh < $^ > [email protected]
+	mv [email protected] $@
+
 ## Fuzzing targets
 
 # list of fuzz targets
@@ -257,4 +270,3 @@
 	/usr/bin/xxd -i -a keyr >> hostkeys.c
 	/usr/bin/xxd -i -a keye >> hostkeys.c
 	/usr/bin/xxd -i -a keyd >> hostkeys.c
-