add debugging

Dockerfile.debian-bullseye-directory-listing

@@ -4,7 +4,7 @@ ENV DEBIAN_FRONTEND=noninteractive
 
 RUN apt-get -qq update && \
     apt-get -qq dist-upgrade && \
-    apt-get -qq install python3 python3-jinja2 && \
+    apt-get -y install python3 python3-jinja2 libexpat1 && \
     apt-get -qq clean
 
 COPY directory-listing/create-index.py /usr/local/bin/create-directory-html-index