Ludovic Courtès writes:

> The ‘emacs’ package currently doesn’t have a ‘debug’ output.  So you
> would first need to add one:
>
>   (outputs '("out" "debug"))
>
> and then install both outputs:
>
>   guix package -i emacs emacs:debug
>
> See
> <https://www.gnu.org/software/guix/manual/html_node/Installing-Debugging-Files.html>.

Thank you!  Very nice documentation.  As discussed on IRC it was needed
to not use grafts to avoid gdb `CRC mismatch'

    guix package --no-grafts -i emacs emacs:debug

I also set

    ~/.gdbinit
    set debug-file-directory ~/.guix-profile/lib/debug

and did

    guix build --source emacs
    tar xf /gnu/store/wqdh5lxyrkzjhxy2rvs7qsbrd07lw89i-emacs-25.1.tar.xz

and set

    (gdb) directory ~/src/guix/emacs-25.1/src

Now I have a full backtrace; attached.

I'm not sure how to continue here; I built Emacs from GIT and there the
problem is not present.  Looking at the diff from 25.1 until HEAD I do
not see any obvious patches, neither does the git log point me to one.

Greetings,
Jan