[luatex] MWE now failing with recent TeX Live update

[Javier Bezos]

> I wouldn't do it in a real document, it was only because I tried to
> find out the minimal code needed to get working hyphenation.
>
> But why does it give an error that \bbl at csarg is undefined? Is that
> to be expected?

Yes, \bbl at patterns@lua is babel proper. It selects the \language
and loads the patterns file if necessary. It also marks the file
as 'loaded' for both babel and luatex-hyphen (the macro names are
different, and while luatex-hyphen creates an empty macro, the
corresponding babel macro contains the files loaded). Since
it's babel, expect further errors. On the other hand, I wrote
the language.dat loader thinking in contexts where babel is not
used.

Javier