Of late I've been getting occasional Emacs crashes with the following backtrace:
$ emacs -nw
Fatal error 11: Segmentation fault
Backtrace:
emacs[0x4fbdb2]
emacs[0x4e3389]
emacs[0x4fa83e]
emacs[0x4faa43]
emacs[0x4faaaf]
/usr/lib/libpthread.so.0(+0x11080)[0x7f1ebfa42080]
emacs(re_search_2+0x38c)[0x53168c]
emacs[0x526c12]
emacs[0x527565]
emacs[0x527747]
emacs[0x554416]
emacs[0x58a32b]
emacs[0x553e7d]
emacs[0x55426b]
emacs[0x58a32b]
emacs[0x553e7d]
emacs[0x55426b]
emacs[0x58a32b]
emacs[0x553e7d]
emacs[0x55426b]
emacs[0x58a32b]
emacs[0x55426b]
emacs[0x5544dc]
emacs[0x552695]
emacs[0x554351]
emacs[0x58a32b]
emacs[0x55426b]
emacs[0x58a32b]
emacs[0x55426b]
emacs[0x58a32b]
emacs[0x55426b]
emacs[0x552de6]
emacs[0x42abca]
emacs[0x437f5f]
emacs[0x438087]
emacs[0x43c3ea]
emacs[0x440ca2]
emacs[0x43f105]
emacs[0x44a3c8]
emacs[0x44d00a]
emacs[0x460b9e]
...
Segmentation fault (core dumped)