bug#53809: 29.0.50; fatal error: assertion failed: string_immovable_p (bytestr)

[Gregor Zattler]

Hi Mattias,
* Mattias Engdegård <mattiase@acm.org> [2022-02-07; 16:01]:
> 7 feb. 2022 kl. 15.30 skrev Eli Zaretskii <eliz@gnu.org>:
>
>>> Lisp Backtrace:
>>> "gnus-alias-init" (0xffffacc0)
>
> What is that `gnus-alias-init`? I can't find anything like it in the Emacs 
> tree.

It's from a package, called gnus-alias, which is rather old.
It allows for automatic stetting of some email headers
according to correspondent.
https://melpa.org/#/gnus-alias

With the technical details, I cannot help, sorry.

Thanks, Gregor