我将映像从 16.04 更新为 ubuntu 20.04，并将 grub 升级为 grub2。从系统日志中，我观察到以下错误：
Oct 19 10:30:10 host-1 systemd[1]: Starting GRUB failed boot detection...
Oct 19 10:30:10 host-1 grub-editenv[533]: /usr/bin/grub-editenv: error: cannot open `/boot/grub/grubenv.new': No such file or directory.
Oct 19 10:30:10 host-1 systemd[1]: grub-initrd-fallback.service: Main process exited, code=exited, status=1/FAILURE
Oct 19 10:30:10 host-1 systemd[1]: grub-initrd-fallback.service: Failed with result 'exit-code'.
Oct 19 10:30:10 host-1 systemd[1]: Failed to start GRUB failed boot detection.
我该如何修复此问题？
我的 grub 分区的内容：
/boot/grub# ls
device.map fonts gfxblacklist.txt grub.cfg grubenv grub-mkconfig_lib grub-multi-install i386-pc unicode.pf2