I've been stuck on trying to "infect" an Ubuntu VPS with Guix for a
while. It keeps failing on the bootloader setup step and it does so in
a way that somehow nukes the `guix` command, but the store remains.

At press time, my config was the one attached.

As I'm a caveperson who never owned a single UEFI machine, I'm a bit
stumped as to what the absolute heck the nature of the error might be:
```
# guix system init /etc/config.scm /
...bunch of build stuff, and then:
guix system: error:
'/gnu/store/0az53wrhxvhpkm80pmfyzw607y0qas9n-grub-efi-2.04/sbin/grub-install
--boot-directory //boot --bootloader-id=Guix --efi-directory
//boot/efi' exited with status 1; output follows:

  /gnu/store/0az53wrhxvhpkm80pmfyzw607y0qas9n-grub-efi-2.04/sbin/grub-install:
  error:
  /gnu/store/0az53wrhxvhpkm80pmfyzw607y0qas9n-grub-efi-2.04/lib/grub/i386-pc/modinfo.sh
  doesn't exist. Please specify --target or --directory.
```

I found two existing guides, but one requires adding an extra block
device and other shenanigans, and the other mentions some alarmingly
outdated version numbers, so I don't trust either of them.