improve checks

lib/smoketest.sh

@@ -107,7 +107,7 @@ select_scenarios() {
 }
 
 smoketest_run() {
-  local tier=pr ref=HEAD keep=0 names=()
+  local tier="pr" ref=HEAD keep=0 names=()
   while (( $# > 0 )); do
     case "$1" in
       --tier) tier="${2:-}"; shift 2 || die "--tier needs pr or all" ;;
@@ -338,7 +338,9 @@ smoketest_shell() {
   mkdir -p "$dir"
   qemu-img create -q -f qcow2 -b "$IMAGES/$image.qcow2" -F qcow2 "$dir/disk.qcow2"
   vm_start "$dir" "$dir/disk.qcow2"
-  trap 'vm_kill; rm -rf "$dir"' EXIT
+  # Expanded now: $dir is local, and gone by the time the script exits
+  # shellcheck disable=SC2064
+  trap "vm_kill; rm -rf $(printf '%q' "$dir")" EXIT
   echo "Starting a throwaway copy of the $image image..."
   vm_wait_up
   vm_ssh -t