change from append to overwrite

Makefile

@@ -31,13 +31,15 @@ $(BUILD_ROOT)/%.o: $(SRC_ROOT)/%.c $(HEADERS)
 
 unified:
 	# roll together the headers. api.h needs to come first so we sort the headers.
-	cat $(sort $(HEADERS)) >> $(BUILD_ROOT)/statepoint.h
+	cat $(sort $(HEADERS)) > $(BUILD_ROOT)/statepoint.h
 	# make the C file
 	echo "#include \"statepoint.h\"" > $(BUILD_ROOT)/statepoint.c
 	sed -E -e "s:[[:space:]]*#include[[:space:]]+\"include/.+\":// include auto-removed:g" $(C_SRCS) >> $(BUILD_ROOT)/statepoint.c
 	# ensure that it compiles
 	$(CC) -c $(BUILD_ROOT)/statepoint.c -o $(BUILD_ROOT)/statepoint.o
+	tar cvf unified-source.tar $(BUILD_ROOT)/statepoint.c $(BUILD_ROOT)/statepoint.h
 
 clean:
 	rm -f build/*
 	rm -f dist/*
+	rm -f unified-source.tar