Ubuntu Canary fails to install using a basic manual partitioning layout

Hardware: HP Z220 SFF Workstation, 32 GB RAM, 250 GB SSD + 1 TB SSD, UEFI, no secure boot. Testing is being done in a VM made with pure QEMU+KVM, SeaBIOS, 4 GB RAM, 2 CPU cores, and 20 GB disk space.

Steps to reproduce bug:

1: Boot the latest Ubuntu Canary ISO in a VM with the specified specs.
2: Launch the Ubuntu installer, and proceed through the installation steps until you reach the "Installation type" screen.
3: When you get to "Installation type", select "Something else".
4: Create a single ext4 partition, accept the default size, and set the mount point to "/".
5: Proceed through the rest of the installation steps.

Expected result: Ubuntu should install successfully, and no visible errors should occur during the installation process.
Actual result: Several "System program problem detected" messages show up during the installation process, and the installation fails.

Notes:

I looked at the logs after the installation failed by pressing the "View logs" button in the installer, and there didn't appear to be any obvious errors.

I also tried installing Ubuntu using the "Erase disk" option, and the installation succeeded in this instance. The partitioning layout offered by the "Erase disk" option appeared very similar to the layout I set with manual partitioning.

One of the "System program problem detected" messages appeared when the installation failed. Alas, I didn't tell it to send the problem report, so... oops. But I reproduced the bug twice, so it shouldn't be hard to get the problem report again. I can reproduce the bug and send the system program problem report if needed.

ProblemType: Bug
DistroRelease: Ubuntu 22.10
Package: subiquity (unknown)
ProcVersionSignature: Ubuntu 5.15.0-27.28-generic 5.15.30
Uname: Linux 5.15.0-27-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu82
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.472
CrashDB:
 {
        "impl": "launchpad",
        "project": "subiquity",
        "bug_pattern_url": "http://people.canonical.com/~ubuntu-archive/bugpatterns/bugpatterns.xml"
     }
CurrentDesktop: ubuntu:GNOME
Date: Mon Jun 6 04:34:10 2022
LiveMediaBuild: Ubuntu 22.10 "Kinetic Kudu" - Alpha amd64 (20220603)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=C.UTF-8
 SHELL=/bin/bash
SourcePackage: subiquity
UpgradeStatus: No upgrade log present (probably fresh install)