Updated with a suggestion from Jim Meyering to use the '-d'
option to ls to avoid a future case of directories matching.
# without arch second.
arch=$(echo "@host_cpu@" | sed 's/^i.86$/i?86/')
-kernels=$(ls -1vr /boot/vmlinuz-*.$arch* 2>/dev/null | grep -v xen; ls -1vr /boot/vmlinuz-* 2>/dev/null | grep -v xen)
+kernels=$(ls -1dvr /boot/vmlinuz-*.$arch* 2>/dev/null | grep -v xen; ls -1dvr /boot/vmlinuz-* 2>/dev/null | grep -v xen)
+
+if [ -z "$kernels" ]; then
+ echo "$0: failed to find a suitable kernel in /boot directory" >&2
+ exit 1
+fi
+
for f in $kernels; do
b=$(basename "$f")
b=$(echo "$b" | sed 's,vmlinuz-,,')