On 2/5/2022 2:35 PM, Bruno Le Floch wrote:
> On 2022-02-05 13:48, Hans Hagen wrote:
>> this append and prepend mechanism started out as an experiment and it
>> has some nasty pitfalls (esp when local and global get mixed) so that
>> is why it has its own handler
>
> Bug related to this: prefixing \toksapp and similar gives a Fatal error,
> where I would expect either that it works, or errors with "You can't use
> a prefix with \toksapp".  (Here I'm removing unrelated lines in the
> output.)
>
> $ luatex '\global\toksapp'
> This is LuaTeX, Version 1.13.2 (TeX Live 2021)
> ! This can't happen (prefix).
> <*> \global\toksapp
> !  ==> Fatal error occurred, no output PDF file produced!
that can be fixed