fail properly if VERSION not set

diff --git a/contrib/samples/refentry/bind9/Makefile b/contrib/samples/refentry/bind9/Makefile
index c7649d90cc35f09fa6e66985eb7240c790e0b112..93a878052346c62eec3ef8dd585bc8e1ea6a191a 100644 (file)
--- a/contrib/samples/refentry/bind9/Makefile
+++ b/contrib/samples/refentry/bind9/Makefile
@@ -17,8 +17,8 @@ all: man
 
 $(FILE):
 ifeq ($(VERSION),)
-       @echo 'See http://ftp.isc.org/isc/bind9/'
-       @echo 'Specify a VERSION; e.g., "make VERSION=9.4.0b2" to download 9.4.0b2'
+       $(warning See http://ftp.isc.org/isc/bind9/)
+       $(error Specify a VERSION; e.g., "make VERSION=9.4.0b2" to download 9.4.0b2)
        @echo
 endif
        (cd $(TMP); $(WGET) $(WGETFLAGS) $(BASEURL)/$(SUBDIR)/$(DOWNLOAD_FILENAME))