bug#42832: 28.0.50; "Bus error" when compiling Emacs now on Debian bullseye

[Pip Cet <pipcet@gmail.com>]

On Thu, Aug 13, 2020 at 10:15 AM Lars Ingebrigtsen <larsi@gnus.org> wrote:
> Lars Ingebrigtsen <larsi@gnus.org> writes:
> > I'll try compiling without dbus and see what happens.
>
> With ./configure --without-dbus, "make bootstrap" doesn't error out for
> me.

So even though the hash table wasn't the dbus hash table, omitting the
dbus code somehow avoids the problem? Odd.

All that sounds to me like we ought to dig down into the core file and
figure out what happened, since the issue is likely to remain present
otherwise and it seems somewhat difficult to track down and reproduce.

The other odd thing is that 0xc000000018000000. That looks like a
GC-marked pseudovector header, but I've checked and can't find
anything that would generate PVEC_COMPILEDs of length 0, which would
be a severe bug.

Can you find out which hash table lives at 0x7ffff19a41a8? I'd suggest
something like "find &globals,&globals+1,0x7ffff19a41ad" to get the
offset in globals, if it is a global variable, then looking it up with
"ptype/o globals".

(If you don't have the time, I'd be happy to look at the core file
myself, if we can arrange that).