follow shellcheck for install-yubikey

install-yubikey.sh

@@ -1,3 +1,5 @@
+#!/usr/bin/env bash
+
 rbtohex() {
     ( od -An -vtx1 | tr -d ' \n' )
 }
@@ -64,7 +66,7 @@ mkfs.btrfs -L "$FSROOT" "/dev/partitions/$FSROOT"
 #touch /mnt-root/nix-store.squashfs
 
 mount "/dev/partitions/$FSROOT" /mnt
-cd /mnt
+cd /mnt || exit
 btrfs subvolume create root
 btrfs subvolume create home
 cd
@@ -167,6 +169,6 @@ cat > /mnt/etc/nixos/configuration.nix <<'endmsg'
 
 endmsg
 
-cd /mnt
+cd /mnt || exit
 nixos-install --root /mnt
 passwd