set unbound in build-themes

build-themes.sh

@@ -9,8 +9,8 @@ if [[ "$1" == "--watch" && -n "$2" ]]; then
   [[ $(basename "$file") = _* ]] && exit 1
   sass --no-source-map --watch "$file" "$css_dir/theme-$(basename "$file" .scss).css"
 else
+  set -u
   rm -r "$css_dir/"
-
   #build default first
   sass --no-source-map "$sass_dir/_default.scss" "$css_dir/style.css"
   for file in "$sass_dir"/*.scss; do