rb_reg_error_desc  701 re.c               rb_exc_raise(rb_reg_error_desc(str, options, err));
rb_reg_error_desc 2620 re.c           	return rb_reg_error_desc(str, 0, err);
rb_reg_error_desc 2857 re.c           	rb_set_errinfo(rb_reg_error_desc(str, options, err));