Comment # 12 on bug 1174412 from Fabian Vogt

(In reply to Andr�s Barrantes Silman from comment #9)
> You're right!
> Aparantely there is /boot/efi/EFI...

That's normal - /boot/efi is the mountpoint of the ESP, which has everything
below /EFI.

So if /boot/efi/EFI exists, why does test -d /boot/efi in shim-install fail?
Maybe this helps:

findmnt
test -d /boot/efi && echo "exists"
grub2-probe --target=disk --device-map= /boot/efi
grub2-probe --target=drive --device-map= /boot/efi
bash -x shim-install --efi-directory /boot/efi

AFAICT this is an unrelated issue though. Either /boot/efi is mounted as the
wrong partition (which AFAICT is unlikely), grub2-probe is returning the wrong
device or libefiboot translates the path wrong.

Does this result in a working boot entry?
efibootmgr -c -d /dev/nvme0n1 -p 1 -w -L efibootmgr-manual -l
'\EFI\opensuse\shim.efi'