The following files contain only a relative path to a non-existing directory in the repository:
nikola/data/themes/base/assets/css/baguetteBox.min.css
nikola/data/themes/bootblog4-jinja/assets/css/bootblog.css
nikola/data/themes/bootstrap4/assets/css/bootstrap.min.css
nikola/data/themes/bootstrap4-jinja/assets/css/bootstrap.min.css