In these days, I got following with make release:

cc -Os -mmultiple -pipe -Werror -Wall -Wpointer-arith
 -Wstrict-prototypes -Wmissing-prototypes -Wno-uninitialized -Wno-main
 -msoft-float -I. -I/ export/20010629/sys/arch -I/export/20010629/sys
 -nostdinc -DMAXUSERS=12 -D_KERNEL -D_KERNEL_OPT -Dmacppc -c
 /export/20010629/sys/arch/macppc/dev /if_mc.c

cc1: warnings being treated as errors

/export/20010629/sys/arch/macppc/dev/if_mc.c:373: warning:
  `mc_mediachange' defined but not used

/export/20010629/sys/arch/macppc/dev/if_mc.c:399: warning:
  `mc_mediastatus' defined but not used *** Error code 1

Stop.

My work arround is:

--- 20010629/sys/arch/macppc/dev/if_mc.c-ooo	Fri Jun  8 19:41:51 2001
+++ 20010629/sys/arch/macppc/dev/if_mc.c	Sun Jul  1 17:53:05 2001
@@ -67,8 +67,8 @@
 hide void	mc_reset_txdma __P((struct mc_softc *sc));
 hide void	mc_select_utp __P((struct mc_softc *sc));
 hide void	mc_select_aui __P((struct mc_softc *sc));
-hide int	mc_mediachange __P((struct mc_softc *sc));
-hide void	mc_mediastatus __P((struct mc_softc *sc, struct ifmediareq *));
+extern int	mc_mediachange __P((struct mc_softc *sc));
+extern void	mc_mediastatus __P((struct mc_softc *sc, struct ifmediareq *));
 
 int mc_supmedia[] = {
 	IFM_ETHER | IFM_10_T,

Am I wrong ?
---
Makoto Fujiwara, Chiba Japan
http://www.ki.nu/software/NetBSD/iBook2/