ChromeOS 安装期间出现 GRUB 定制程序错误

Question

我为 ChromeOS 创建了一个 GRUB 菜单，但在尝试更新 GRUB 时出现错误：

Generating grub configuration file ...
/etc/grub.d/99_brunch: 3: search: not found
/etc/grub.d/99_brunch: 4: loopback: not found
/etc/grub.d/99_brunch: 5: Syntax error: word unexpected (expecting ")")