grub-install /dev/sda

While completing a new install of 2010 ubuntu the install failed at grub-install

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: ubiquity 20.10.10
ProcVersionSignature: Ubuntu 5.8.0-21.22-generic 5.8.13
Uname: Linux 5.8.0-21-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu49
Architecture: amd64
CasperMD5CheckResult: skip
CasperVersion: 1.452
CurrentDesktop: ubuntu:GNOME
Date: Mon Oct 12 17:27:25 2020
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 20.10 "Groovy Gorilla" - Beta amd64 (20201011)
ProcEnviron:
 LANGUAGE=en_CA.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_CA.UTF-8
 LC_NUMERIC=C.UTF-8
RebootRequiredPkgs:
 linux-image-5.8.0-22-generic
 linux-base
 linux-image-5.8.0-21-generic
 linux-base
 linux-base
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)