package:grub-efi-amd64:2.02-2ubuntu8.1 Setting up grub-efi-amd64 (2.02-2ubuntu8.1) ... Use of uninitialized value $reply in scalar chomp at /usr/share/perl5/Debconf/FrontEnd/Passthrough.pm line 66, line 10. Use of uninitialized value $reply in concatenation (.) or string at /usr/share/perl5/Debconf/FrontEnd/Passthrough.pm line 67, line 10. Use of uninitialized value $reply in split at /usr/share/perl5/Debconf/FrontEnd/Passthrough.pm line 68, line 10. Use of uninitialized value in string eq at /usr/share/perl5/Debconf/FrontEnd/Passthrough.pm line 202, line 10. Use of uninitialized value $reply in scalar chomp at /usr/share/perl5/Debconf/FrontEnd/Passthrough.pm line 66, line 10. Use of uninitialized value $reply in concatenation (.) or string at /usr/share/perl5/Debconf/FrontEnd/Passthrough.pm line 67, line 10. Use of uninitialized value $reply in split at /usr/share/perl5/Debconf/FrontEnd/Passthrough.pm line 68, line 10. Use of uninitialized value $ret in string eq at /usr/share/perl5/Debconf/FrontEnd/Passthrough.pm line 212, line 10. Use of uninitialized value $_[1] in join or string at /usr/share/perl5/Debconf/DbDriver/Stack.pm line 111, line 10. Installing for x86_64-efi platform. Installation finished. No error reported. Generating grub configuration file ... Found linux image: /boot/vmlinuz-4.15.0-24-generic Found initrd image: /boot/initrd.img-4.15.0-24-generic Found linux image: /boot/vmlinuz-4.15.0-23-generic Found initrd image: /boot/initrd.img-4.15.0-23-generic Found Windows Boot Manager on /dev/sda1@/EFI/Microsoft/Boot/bootmgfw.efi Adding boot menu entry for EFI firmware configuration done Use of uninitialized value $val in substitution (s///) at /usr/share/perl5/Debconf/Format/822.pm line 83, line 13. Use of uninitialized value $val in concatenation (.) or string at /usr/share/perl5/Debconf/Format/822.pm line 84, line 13. dpkg: error processing package grub-efi-amd64 (--configure): installed grub-efi-amd64 package post-installation script subprocess returned error exit status 128