grub did not get installed on fresh install

[Nenad Đapić]

Ubuntu installer reported fatal error while installing grub. I was installing ubuntu on sda7 on asus k556u laptop.

There was win10 already there on sda2, booting from sda1. It used recovery partitions sda3 and sda4. Later one I erased and formed extended partition sda4. On that extended partition I have created boot partition sda5 of type fat32, swap partition at sda6 and sda7 of type ext4 on which I attempted instalation at first attempt. It failed with fatal error while installing grub near the end of installation.

At second attempt to install ubuntu, I did not choose to create partitions. Instead I accepted replacing existing installation of ubuntu on sda7, but it failed with the same grub installer fatal error.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubiquity 20.04.15.2
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27.4
Architecture: amd64
CasperMD5CheckResult: skip
CasperVersion: 1.445.1
CurrentDesktop: ubuntu:GNOME
Date: Fri Feb 12 17:38:14 2021
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
ProcEnviron:
 LANGUAGE=en_US.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 LC_NUMERIC=C.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)