GuixSD installation of external SSD drive: grub-install: error: failed to get canonical path of ` /boot/efi'

[Pierre-Henry F.]

Hello,

I'm trying to install GuixSD on a USB SSD drive.
I downloaded:
[  
https://ftp.gnu.org/gnu/guix/guix-system-install-1.1.0.x86_64-linux.iso.xz.sig](https://ftp.gnu.org/gnu/guix/guix-system-install-1.1.0.x86_64-linux.iso.xz.sig)

Then:
  $ sudo dd if=guix-system-install-1.1.0.x86_64-linux.iso of=/dev/sde

Where `/dev/sde' is a usb drive to boot from.

I connected the USB boot drive and the USB SSD drive where to install GuixSD,
followed the guided install wizard and ended with this error:

  guix system: error: '/gnu/store/...grub-efi-2.04/sbin/grub-install 
--boot-directory /mnt/boot --bootloader-id=Guix --efi-directory /boot/efi' 
exited with status 1; output follows:
  grub-install: error: failed to get canonical path of ` /boot/efi'

How to install GuixSD?

Thanks,
phf