Ubiquity crashes with Low Disk Space

[Sean]

Description: Ubuntu Hirsute Hippo (development branch)
Release: 21.04
ubiquity:
  Installed: 21.04.13
  Candidate: 21.04.13
  Version table:
 *** 21.04.13 500
        500 http://archive.ubuntu.com/ubuntu hirsute/main amd64 Packages
        100 /var/lib/dpkg/status

KVM/Qemu 2GiB mem, e1000, IDE CD ROM, 16GiB (or less) IDE virtual Disk.

* Behaviour
IDE qcow2 virtual disk image 16GiB selected. CD ROM image boots, Desktop is displayed. Dialog appears - "Installation failed -- LKialog ? - The installer encountered an unrecoverable error...".

Repeated test on 12GiB disk - Same Error.
Repeated test on 20GiB disk - Success, ubiquity loads correctly.

* Expected behaviour
Kubuntu Ubiquity continues to load with "Install Kubuntu" button. A warning to user during partitioning of insufficient disk space for Kubuntu install.

No /var/log/partman log present.

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: ubiquity 21.04.13
ProcVersionSignature: Ubuntu 5.11.0-13.14-generic 5.11.7
Uname: Linux 5.11.0-13-generic x86_64
ApportVersion: 2.20.11-0ubuntu61
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.461
CurrentDesktop: KDE
Date: Sun Apr 4 10:19:37 2021
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/kubuntu.seed maybe-ubiquity quiet splash ---
LiveMediaBuild: Kubuntu 21.04 "Hirsute Hippo" - Beta amd64 (20210403)
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Rik Mills (rikmills)]

The logs do not show anything to do with diskspace, but do show the installer crashed with:

malloc(): unaligned tcache chunk detected