Самый компактный (?) способ сделать Segmentation fault

$ perl -e '/(?{??})/'
Segmentation fault

P. S. WTF?

$ perl -Mre=eval -e '$_ = "(?{})"; /(??{$_})/'
Eval-group not allowed at runtime, use re 'eval' in regex m/(?{})/ at -e line 1.