Preparing to unpack .../0-grub-pc_2.02-2ubuntu8.17_amd64.deb ...
Unpacking grub-pc (2.02-2ubuntu8.17) over (2.02-2ubuntu8.14) ...
Preparing to unpack .../1-grub-pc-bin_2.02-2ubuntu8.17_amd64.deb ...
Unpacking grub-pc-bin (2.02-2ubuntu8.17) over (2.02-2ubuntu8.14) ...
Preparing to unpack .../2-grub2-common_2.02-2ubuntu8.17_amd64.deb ...
Unpacking grub2-common (2.02-2ubuntu8.17) over (2.02-2ubuntu8.14) ...
Preparing to unpack .../3-grub-efi-amd64-signed_1.93.19+2.02-2ubuntu8.17_amd64.deb ...
Unpacking grub-efi-amd64-signed (1.93.19+2.02-2ubuntu8.17) over (1.93.15+2.02-2ubuntu8.14) ...
Preparing to unpack .../4-grub-efi-amd64-bin_2.02-2ubuntu8.17_amd64.deb ...
Unpacking grub-efi-amd64-bin (2.02-2ubuntu8.17) over (2.02-2ubuntu8.14) ...
Preparing to unpack .../5-grub-common_2.02-2ubuntu8.17_amd64.deb ...
Unpacking grub-common (2.02-2ubuntu8.17) over (2.02-2ubuntu8.14) ...
Processing triggers for ureadahead (0.100.0-20) ...
ureadahead will be reprofiled on next reboot
Processing triggers for install-info (6.5.0.dfsg.1-2) ...
Setting up grub-common (2.02-2ubuntu8.17) ...
update-rc.d: warning: start and stop actions are no longer supported; falling back to defaults
Processing triggers for systemd (237-3ubuntu10.3) ...
Processing triggers for man-db (2.8.3-2) ...
Setting up grub-efi-amd64-bin (2.02-2ubuntu8.17) ...
Setting up grub-pc-bin (2.02-2ubuntu8.17) ...
Setting up grub2-common (2.02-2ubuntu8.17) ...
Setting up grub-pc (2.02-2ubuntu8.17) ...
Sourcing file `/etc/default/grub'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.15.0-88-generic
Found initrd image: /boot/initrd.img-4.15.0-88-generic
Found linux image: /boot/vmlinuz-4.15.0-29-generic
Found initrd image: /boot/initrd.img-4.15.0-29-generic
Adding boot menu entry for EFI firmware configuration
done
Setting up grub-efi-amd64-signed (1.93.19+2.02-2ubuntu8.17) ...
dpkg: error processing package grub-efi-amd64-signed (--configure):
 installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 255