venti: more detail in index divisor too coarse message
diff --git a/src/cmd/venti/srv/index.c b/src/cmd/venti/srv/index.c
index d751b98..0cb0a03 100644
--- a/src/cmd/venti/srv/index.c
+++ b/src/cmd/venti/srv/index.c
@@ -302,7 +302,7 @@
 	div = (((u64int)1 << 32) + nb - 1) / nb;
 	ub = (((u64int)1 << 32) - 1) / div + 1;
 	if(div < 100){
-		seterr(EBug, "index divisor too coarse");
+		seterr(EBug, "index divisor too coarse [%lld buckets]", nb);
 		return nil;
 	}
 	if(ub > nb){