Error with RequirePackage{amsmath}

[fortierq]

Hello,
I try to use mathtools but I have the following problem :

/usr/local/texlive/2023/texmf-dist/tex/latex/mathtools/mathtools.sty:122: Illegal parameter number in definition of \__hook package/amsmath/after.
<to be read again> 
\Ustopmath 
l.122 \RequirePackage{amsmath}[2016/11/05]

Any idea ?

[FrnchFrgg]

How did you solve this (since you marked as completed) ? BTW I think the bug is actually caused by amsmath and not mathtools

[muzimuzhi]

Most likely, such error was caused by code before loading mathtools, which looked like \AddToHookWithArguments{package/amsmath/after}{#1}, adding some code containing #1 or #<n> to hook package/amsmath/after, with \AddToHookWithArguments.

Since this generic hook has no arguments, no #1, #2, ..., #9 can be used in its code. Doubled-# are accepted, for example

\AddToHook{package/amsmath/after}{\def\x##1{##1}}

\AddToHookWithArguments also works, but it gives a wrong implication that the hook package/amsmath/after is argumented takes arguments.

[car222222]

Nice word: "argumented".
I shall submit it to the OED. 😃

[FrnchFrgg]

Here I do not use mathtools (at least it is not loaded at that point) but lualatex-math triggers the same problem. The workaround I found was to load lualatex-math after amsmath but the documentation of lualatex-math tells that less issues with amsmath and lualatex will be fixed that way.

[u-fischer]

@FrnchFrgg as neither the OP nor you provided a full example it is quite impossible to say what triggers your error.

[muzimuzhi]

See a full example loading lualatex-math and some analysis in phst/lualatex-math#26.