I've modify the place where I inserted code to minimize the number of files touched. (#131)

prepare_assets.sh

@@ -4,7 +4,9 @@ set -e
 DIR=$(dirname "$0")
 
 # install node modules
-yarn install --pure-lockfile --production
+YARN=yarn
+[ -x /usr/bin/lsb_release ] && [ -n "`lsb_release -i | grep Debian`" ] && YARN=yarnpkg
+$YARN install --pure-lockfile --production
 
 # Copy admin-lte dist
 mkdir -p "${DIR}/assets/dist/js" "${DIR}/assets/dist/css" && \