bug#22356: 25.0.50; emacs-25 very crashy with ivy-mode

[Dmitry Gutov <dgutov@yandex.ru>]

On 01/12/2016 09:33 PM, Eli Zaretskii wrote:

> Was anything else on your system updated lately?  Some library,
> perhaps, or some system component?

Only minor updates, as far as I know. I'm on Ubuntu 15.10, which is the 
current stable, but not LTS, distribution. In the last few days, I've 
updated from kernel 4.2.0-22 to 4.2.0-23.

But I've rebooted into the previous version now (it's kept as backup), 
and the problem is still there.

Other applications, however, haven't suddenly become all crashy, 
however. And I use a few (web browser, email client, file manager, video 
player, torrent client). On the sum, they must be more complex than 
Emacs, and they also use libc, I suppose.

 > The problems look quite basic, for
> example this:
>> Program received signal SIGABRT, Aborted.
>> 0x00007ffff14a5267 in __GI_raise (sig=sig@entry=6) at
>> ../sysdeps/unix/sysv/linux/raise.c:55
>> 55	../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
>
> means that glibc detected an invalid pointer being passed to 'free'.
> It's glibc which raises SIGABRT here, AFAIU, and it does that because
> if that invalid 'free' call.

Yes. Another thing I've noticed is that problems sort of clustered by 
type: if I start Emacs many times and repeat the same process, similar 
backtraces could show up for a few times in a row, then change to a 
different kind of error (also repeated a few times), then back...

Another piece of the puzzle: if I run emacs -Q -L <paths to the few 
packages I thought to be responsible: ivy, flx, highlight-tail>, 
recreate ivy's configuration and try it again, the problem doesn't show.

Going to bisect my configuration now.