#102 Problem with recent babel package and language "spanish"

[Martin Sievers]

The recent update of KOMA-Script seems to have a problem with option spanish from babel (v25.17). The error is LaTeX hooks Error: Generic hooks cannot be added to '\@startsection'. Changing to another language or switching to standard book class resolves the problem.

\documentclass{scrbook}
\usepackage[spanish]{babel}

\begin{document}
   Test
\end{document}

[Markus Kohm]

You get the same error with:

\documentclass{book}
\AddToHook{cmd/@startsection/before}{\typeout{Hook Test}}

\usepackage[spanish]{babel}

\begin{document}
   Test
\end{document}

So IMHO this is a babel-spanish issue not a KOMA-Script issue.

BTW: KOMA-Script does not use \@startsection anymore and the new version does no longer redefine it but only adds a hook to warn that several features are no longer available, when using \@startsection. See also [wiki-en:Release 3.49] resp. [wiki-de:Release 3.49].

[U_Fischer]

In some sense it is a KOMA issue, as KOMA is the one doing the patching. Command hooks are quite nice, but they are no fully safe if catcode changes are involved and personally I try to avoid them for long term code. See e.g. https://github.com/latex3/latex2e/issues/1099

[Markus Kohm]

The alternative would be to once again redefine \@startsection, which has been removed to avoid several other issues. So this is not really an option.

[Markus Kohm]

Workaround added in [r4254].