During OS install, GRUB tries installing on sda even when it should install on sdb

[Mark A Gerads]

I tried installing Ubuntu on my dad's laptop, but the installer failed to install GRUB.
I noticed it was trying to install GRUB on /dev/sda even though the EFI partition and the Ubuntu root partition were both on /dev/sdb
I suggest that instead of hard-coding the Ubuntu installer to install on /dev/sda, the Ubuntu installer should dynamically detect the drive which has the EFI partition and install GRUB on that drive.

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: ubiquity (not installed)
ProcVersionSignature: Ubuntu 5.11.0-16.17-generic 5.11.12
Uname: Linux 5.11.0-16-generic x86_64
ApportVersion: 2.20.11-0ubuntu65
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Sat May 1 21:14:34 2021
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
InstallationDate: Installed on 2021-04-03 (28 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity
Symptom: installer
UpgradeStatus: Upgraded to hirsute on 2021-04-23 (9 days ago)

[Steve Langasek (vorlon)]

The log files attached don't show any installation on either sda or sdb:

Apr 3 09:54:35 ubuntu grub-installer: info: Installing grub on '/dev/nvme0n1'

What exactly do you see that tells you it's installing to sda?

[Mark A Gerads (nazgand)]

The log files are from my own computer, not my dad's; I used the ubuntu-bug command to report this bug.
During install, I noticed the installer run "grub-install /dev/sda" right before the installer failed. This happened twice, as I had tried installing Ubuntu to my dad's laptop twice.

[Launchpad Janitor (janitor)]

[Expired for ubiquity (Ubuntu) because there has been no activity for 60 days.]