bug#21666: 25.0.50; Random segfaults

[Eli Zaretskii]

> From: Jorgen Schäfer <jorgen.schaefer@gmail.com>
> Date: Fri, 23 Oct 2015 09:41:35 +0000
> 
> A few more backtraces in various locations, this time around with the gdb
> settings in the Emacs git tree.
> 
> I also upgraded to 2add4a, the problem did not go away.
> 
> Any suggestions on how I can help debug this further? :-)

There's something _very_ weird going on on your system.  For example:

> Lisp Backtrace:
> "car" (0xffff47f0)
> "numberp" (0xffff4938)
> "cond" (0xffff4a78)

This says that 'numberp' calls 'car', which is false, according to my
reading of the code.

What system-wide or Emacs-related changes, excluding "git pull" from
the repository, did you make immediately before this started
happening?  Any system upgrades, new installations, anything else?