Efraim Flashner writes:

>> +           (add-before 'configure 'setenv
>> +             (lambda _
>> +               (setenv "CFLAGS" "-g")))
>>             (add-after 'unpack 'autogen
>>                        (lambda _
>>                          (zero? (system* "sh" "autogen.sh"))))))))))
>
> Couldn't this be a make-flag or a configure-flag?

Yes, as a configure flags also works.  However, I tracked down the
segfault, backported a patch and and now it builds with -O2.

New patch attached.