ubiquity crashes whilst trying to use ubuntu-bug

Multiple identities can be used for authentication:
 1. user,,, (user)
 2. Jon Thackray,,, (jon)
Choose identity to authenticate as (1-2): 2
Password:
polkit-agent-helper-1: pam_authenticate failed: Authentication failure
==== AUTHENTICATION FAILED ===
Error executing command as another user: Not authorized

This incident has been reported.
ERROR: hook /usr/share/apport/package-hooks/source_ubiquity.py crashed:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/apport/report.py", line 228, in _run_hook
    symb['add_info'](report, ui)
  File "/usr/share/apport/package-hooks/source_ubiquity.py", line 158, in add_info
    add_installation_log(report, 'Casper', 'casper.log')
  File "/usr/share/apport/package-hooks/source_ubiquity.py", line 29, in add_installation_log
    if isinstance(report[ident], bytes):
  File "/usr/lib/python3.8/collections/__init__.py", line 1010, in __getitem__
    raise KeyError(key)
KeyError: 'Casper'

My installation doesn't have /var/log/partman

jon@frobenius:/var/lib$ lsb_release -rd
Description: Ubuntu 20.04.2 LTS
Release: 20.04

jon@frobenius:/var/lib$ apt-cache policy ubiquity
ubiquity:
  Installed: (none)
  Candidate: 20.04.15.11
  Version table:
     20.04.15.11 500
        500 http://gb.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
     20.04.15 500
        500 http://gb.archive.ubuntu.com/ubuntu focal/main amd64 Packages

I expected to be able to report a bug I've found in qmail-run, but this seems to be a barrier to entry

Instead I got to report ubiquity preventing me from reporting a bug

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubiquity (not installed)
ProcVersionSignature: Ubuntu 5.8.0-53.60~20.04.1-generic 5.8.18
Uname: Linux 5.8.0-53-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.17
Architecture: amd64
CasperMD5CheckResult: skip
Date: Sat May 22 13:36:26 2021
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed maybe-ubiquity quiet splash ---
InstallationDate: Installed on 2021-05-14 (8 days ago)
InstallationMedia: Ubuntu 20.04.2.0 LTS "Focal Fossa" - Release amd64 (20210209.1)
SourcePackage: ubiquity
Symptom: installation
UpgradeStatus: No upgrade log present (probably fresh install)