rb_vm_register_special_exception 1669 eval.c             rb_vm_register_special_exception(ruby_error_reenter, rb_eFatal, "exception reentered");
rb_vm_register_special_exception 9496 gc.c               rb_vm_register_special_exception(ruby_error_nomemory, rb_eNoMemError, "failed to allocate memory");
rb_vm_register_special_exception 2952 proc.c             rb_vm_register_special_exception(ruby_error_sysstack, rb_eSysStackError, "stack level too deep");
rb_vm_register_special_exception 4801 thread.c           rb_vm_register_special_exception(ruby_error_closed_stream, rb_eIOError, "stream closed");
rb_vm_register_special_exception 1063 vm_core.h      void rb_vm_register_special_exception(enum ruby_special_exceptions sp, VALUE exception_class, const char *mesg);