This is related to issues with iconv on alpine linux (see [1]). I
noticed that the content file `tipuesearch_content.json` didn't contain
the sanitized text, but only the boolean `false`. I tracked it down to
the `iconv` call. After migration to the debian docker image it is
working fine. Build was started using `docker run --rm -it -w /build -v
"$PWD":/build daux/daux.io daux generate`.
[1] https://github.com/docker-library/php/issues/428