\input regression-test.tex
\documentclass{article}
% No targetlang, no \olsTargetLanguage, no language package, no
% \DocumentMetadata language -- and 'en' is not among the selectable
% languages, so the old hardcoded 'en' fallback would have failed the
% subsequent "target must be a selectable language" check. The fallback
% must pick the first selectable language instead.
\usepackage[
  languages={de,fr}
]{langselect}
\begin{document}
\START
\TYPE{target=\olsTargetLanguage}
\END
\end{document}