Reconfigure system hangs at bootloader

[aspic]

Hi,
I'm new here and face a system reconfigure issue :

guix system reconfigure /etc/config.scm

... guix system: error: 
'/gnu/store/xskzz78ivbsks4xhng8whyl0x3waw3sm-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/xskzz78ivbsks4xhng8whyl0x3waw3sm-grub-efi-2.04/sbin/grub-install : 
erreur : 
/gnu/store/xskzz78ivbsks4xhng8whyl0x3waw3sm-grub-efi-2.04/lib/grub/i386-pc/modinfo.sh 
n'existe pas. Veuillez utiliser --target ou --directory.


So, verified :
ls /gnu/store/xskzz78ivbsks4xhng8whyl0x3waw3sm-grub-efi-2.04/lib/grub/
x86_64-efi/

My bootloader config.scm :
(bootloader
    (bootloader-configuration
      (bootloader grub-efi-bootloader)
      (target "/boot/efi")

grub-efi is installed and I have a /boot/efi partition.
I can boot Guix from the Debian Grub menu for now.

Thanks for any clue.