update-manager crashed with SIGSEGV in g_callable_info_free_closure()

i had actually just updated from the commandline. after a short while update manager put up a dialog saying it needed to restart and offering to restart now or later. i chose now. *After* the reboot, and on logging in again, this error occurred. and several more errors from apport-gtk which probably aren't being reported because it keeps crashing when i tell it to send again.

ProblemType: Crash
DistroRelease: Ubuntu 21.10
Package: update-manager 1:21.10.4
ProcVersionSignature: Ubuntu 5.13.0-16.16-generic 5.13.13
Uname: Linux 5.13.0-16-generic x86_64
ApportVersion: 2.20.11-0ubuntu68
Aptdaemon:

Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Tue Sep 14 10:30:27 2021
ExecutablePath: /usr/bin/update-manager
InstallationDate: Installed on 2021-01-17 (241 days ago)
InstallationMedia: Ubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
InterpreterPath: /usr/bin/python3.9
PackageArchitecture: all
ProcCmdline: /usr/bin/python3 /usr/bin/update-manager --no-update --no-focus-on-map
ProcEnviron:
 LANGUAGE=en_GB:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_GB.UTF-8
 SHELL=/usr/bin/zsh
Python3Details: /usr/bin/python3.9, Python 3.9.7, python3-minimal, 3.9.4-1
PythonDetails: N/A
SegvAnalysis:
 Segfault happened at: 0x7f9b8c226cec <g_callable_info_free_closure+12>: mov 0x8(%rax),%rdi
 PC (0x7f9b8c226cec) ok
 source "0x8(%rax)" (0x441f0f66e307) not located in a known VMA region (needed readable region)!
 destination "%rdi" ok
SegvReason: reading unknown VMA
Signal: 11
SourcePackage: update-manager
StacktraceTop:
 g_callable_info_free_closure () from /lib/x86_64-linux-gnu/libgirepository-1.0.so.1
 ?? () from /usr/lib/python3/dist-packages/gi/_gi.cpython-39-x86_64-linux-gnu.so
 ?? ()
 ?? ()
 ?? ()
Title: update-manager crashed with SIGSEGV in g_callable_info_free_closure()
UpgradeStatus: Upgraded to impish on 2021-07-08 (69 days ago)
UserGroups: adm cdrom dip lpadmin lxd plugdev sambashare sudo
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