bug#22120: Another backtrace

[Eli Zaretskii]

> From: Eric Hanchrow <eric.hanchrow@gmail.com>
> Date: Thu, 10 Dec 2015 18:42:19 +0000
> 
> What little I could get of the variables' values is at the bottom.

It doesn't tell much.

Can you try reproducing this in an unoptimized build?  It's very hard
to debug optimized code when we suspect some more or less random
corruption of values.  If the problem happens in an unoptimized build,
we won't need to look so hard for bad values.

Also, it looks like you configured with --enable-check-lisp-object-type,
is that right?  If so, please configure without it, that would allow
to see many values directly in the backtrace, instead of asking you to
print them in GDB.

Thanks.