bug#11257: http://thread.gmane.org/gmane.emacs.orgmode/54775

[Chong Yidong]

Marius Hofert <marius.hofert@math.ethz.ch> writes:

> I used "M-x set-variable <RET> debug-on-error <RET> t" to set Emacs in
> debug mode. After this change, I just changed buffers until it crashed
> again. I thought I'm lucky but apparently not: How do I obtain a
> "Backtrace buffer" when Emacs crashes... ? After a restart, there was
> no such buffer :-(

You have to compile Emacs from source, start Emacs from inside GDB from
inside the Emacs src/ directory (run "gdb emacs", then "r" at the GDB
prompt), and trigger the crash.  Then use the command "bt" in GDB to
view the backtrace.