bug#61960: 30.0.50; Unexec build reliably crashes during loadup

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Andrea Corallo <akrl@sdf.org>
>> Cc: 61960@debbugs.gnu.org, hi-angel@yandex.ru
>> Date: Tue, 07 Mar 2023 14:59:24 +0000
>> 
>> >   if test "${with_native_compilation}" != "no"; then
>> >       if test "${HAVE_PDUMPER}" = no; then
>> >     AC_MSG_ERROR(['--with-native-compilation' requires 
>> > '--with-dumping=pdumper'])
>> >       fi
>> 
>> So IIUC we can compile emacs with both unexec and pdumper support, they
>> are not mutually exclusive, and we can specify which one to use for the
>> first dump with --with-dumping.
>> 
>> So yeah I think we have to prevent native compilation to be compiled
>> with unexec support, even if it's not the way Emacs is dumped the first
>> time.
>
> OK, then a simple change to the above condition (and maybe a slight
> change in the message wording as well) should achieve that, right?

Emacs can't be built with both unexec and pdumper dumping, and configure
doesn't let you do that.  So what we have is fine.