So, with this fixed:

On Sat, Dec 06, 2025 at 04:06:29PM -0800, Andrew Hewus Fresh wrote:
> -	_parts=$(disklabel $_disk | sed -En "/.*RAID.*/s/^  \(.\): .*/\1/p")
> +	_parts=$(disklabel $_disk | sed -En "/.*RAID.*/s/^  (.): .*/\1/p")
>  	if [[ -n $_parts ]]; then

It's time to fix the next line.

(I did read through the rest of the function this time)

Comments, OK?

Index: install.sub
===================================================================
RCS file: /cvs/src/distrib/miniroot/install.sub,v
diff -u -p -r1.1282 install.sub
--- install.sub	7 Dec 2025 00:25:59 -0000	1.1282
+++ install.sub	9 Dec 2025 03:25:29 -0000
@@ -3123,7 +3123,7 @@ pick_keydisk() {
 
 	make_dev $_disk
 	_parts=$(disklabel $_disk | sed -En "/RAID/s/^  ([$PARTITIONS]): .*/\1/p")
-	if [[ -n $_parts ]]; then
+	if [[ -z $_parts ]]; then
 		echo "$_disk must contain a RAID partition."
 		return 1
 	fi