Sam Halliday <sam.halliday@gmail.com> writes:
>
> Could somebody please let me know how to dig into 0x56e5508 (if
> relevant)? I have never used gdb in anger.

See if you can adapt the .gdbinit modifications I posted in
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=24358#53; assuming your
recipe always triggers the crash in the exact same way, it might be
enough just to change the conditional to 'if (lim == 1156)', and you
might not even need the ignore call at all.

> I've attempted to workaround this in ensime by simplifying our loading
> of the .ensime file (the s-expression) to use with-temp-buffer and not
> declaring .ensime as an emacs-lisp file... it may be that one of my
> minor modes, active in emacs-lisp, is performing a regexp that is
> triggering this bug.

If you can get the lisp backtrace it should show you what code is
triggering the regexp search.  It should show up automatically when you
do bt, if you've sourced src/.gdbinit as described in etc/DEBUG
"Configuring GDB".