Eli Zaretskii <eliz@gnu.org> writes:

> branch: scratch/igc
> commit 7057c3562ff373c6061b2b9e6d124fb5f6b90ee5
> Author: Jeff Walsh <fejfighter@gmail.com>
> Commit: Eli Zaretskii <eliz@gnu.org>
>
>     * src/pgtkterm.c (mark_pgtkterm): Exclude from MPS builds.
> ---
>  src/pgtkterm.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/src/pgtkterm.c b/src/pgtkterm.c
> index 49b7ea406f8..7279f5d863b 100644
> --- a/src/pgtkterm.c
> +++ b/src/pgtkterm.c
> @@ -336,6 +336,7 @@ evq_flush (struct input_event *hold_quit)
>    return n;
>  }
> 
> +#ifndef HAVE_MPS
>  void
>  mark_pgtkterm (void)
>  {
> @@ -369,6 +370,7 @@ mark_pgtkterm (void)
>       mark_object (device->name);
>      }
>  }
> +#endif
> 
>  char *
>  get_keysym_name (int keysym)

Doesn't this require that device structures be registered and
deregistered as GC roots when allocated and deallocated?  The same
applies to objects in the module's private event queue.