There is no '-r' flag for disklabel.
Index: Makefile
===================================================================
RCS file: /cvs/src/sys/arch/i386/stand/Makefile,v
retrieving revision 1.15
diff -u Makefile
--- Makefile 25 Nov 2007 18:25:31 -0000 1.15
+++ Makefile 4 Mar 2010 21:51:27 -0000
@@ -15,7 +15,7 @@
sudo dd if=/dev/zero of=/dev/rfd0a count=144 bs=10240
prep-fd0:
- sudo disklabel -rw fd0 floppy
+ sudo disklabel -w fd0 floppy
sudo newfs -O 0 -m 0 -o space -i 3000 -c 80 /dev/rfd0a
.include <bsd.subdir.mk>
