bug#41321: 27.0.91; Emacs aborts due to invalid pseudovector objects

[Andy Moreton]

On Sun 24 May 2020, Pip Cet wrote:

> On Sun, May 24, 2020 at 2:24 PM Eli Zaretskii <eliz@gnu.org> wrote:
>> > From: Pip Cet <pipcet@gmail.com>
>> > Date: Sat, 23 May 2020 23:54:17 +0000
>> > Cc: Stefan Monnier <monnier@iro.umontreal.ca>, 41321@debbugs.gnu.org
>> >
>> > I think I've worked it out: it's this mingw bug:
>> > https://sourceforge.net/p/mingw-w64/bugs/778/
>>
>> Thank you for working on this tricky problem.
>>
>> FTR, I don't use that flavor of MinGW.
>
> So your flavor is even more broken than what Debian ships? That's
> interesting, which flavor is it?

FYI, there are two separate projects:
  mingw.org: 32bit only.
  mingw-w64: 32bit and 64bit, using a different C runtime.

On my machine a simple test program shows:

--------------------------------------------------------------
  project     gcc     cpu   alignof(max_align_t)
--------------------------------------------------------------
mingw.org   9.2.0    i686   16
mingw-w64  10.1.0    i686   16 (stdint.h before stddef.h)
                             8 (stdint.h after  stddef.h)
mingw-w64  10.1.0  x86_64   16
--------------------------------------------------------------

This problem only appears with the 32bit mingw-w64 toolchain.

Eli uses the mingw.org toolchain. Linux distros initially used
mingw.org, but switched to mingw-w64 cross compilers several years ago.

    AndyM