package:shim-signed:1.32~16.04.1+0.9+1474479173.6c180c6-1ubuntu1
Setting up grub-efi-amd64-signed (1.66.14+2.02~beta2-36ubuntu3.14) ...
Installing for x86_64-efi platform.
grub-install: error: /boot/efi doesn't look like an EFI partition.
.
dpkg: error processing package grub-efi-amd64-signed (--configure):
 subprocess installed post-installation script returned error exit status 1