software-properties-gtk crashed with TypeError in new_init(): could not convert value for property `transient_for' from DialogCacheOutdated to GtkWindow

[Seija K.]

Upon attempting to add debug repositories to apt and then opening Software Updater, the cache loaded and then I switched to the Ubuntu Software Tab. I then clicked the checkmark next to "software restricted by copyright or legal issues." I then clicked the Close button, and then the reload button.

The window that shows the reload process became stuck and would not be dismissed, softlocking me in the update-manager app and forcing me to kill the application.

Expected Results:
Software Update applies the changes without issue and then quits, or throws and error if that is not possible and I made a mistake

Actual Results:
Software Update manager hangs ans softlocks me into forcing me to kill the process.

Prior to the issue occurring, I ran "echo -e "deb http://ddebs.ubuntu.com $(lsb_release -cs)-updates main restricted universe multiverse\ndeb http://ddebs.ubuntu.com $(lsb_release -cs)-proposed main restricted universe multiverse" | sudo tee -a /etc/apt/sources.list.d/ddebs.list" and then opened Software Update manager. I was attempting to follow the steps to debug on this URL: https://wiki.ubuntu.com/DebuggingProgramCrash

However, I skipped the first step in adding the debug repositories and added the one in the second step before opening Software & Updates.

Description: Ubuntu 19.10
Release: 19.10

software-properties-gtk:
  Installed: 0.98.5
  Candidate: 0.98.5
  Version table:
 *** 0.98.5 500
        500 http://us.archive.ubuntu.com/ubuntu eoan/main amd64 Packages
        500 http://us.archive.ubuntu.com/ubuntu eoan/main i386 Packages
        100 /var/lib/dpkg/status

ProblemType: Crash
DistroRelease: Ubuntu 19.10
Package: software-properties-gtk 0.98.5
ProcVersionSignature: Ubuntu 5.3.0-23.25-generic 5.3.7
Uname: Linux 5.3.0-23-generic x86_64
ApportVersion: 2.20.11-0ubuntu8.2
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Wed Nov 27 11:34:09 2019
ExecutablePath: /usr/bin/software-properties-gtk
ExecutableTimestamp: 1562940163
InstallationDate: Installed on 2019-11-20 (6 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
InterpreterPath: /usr/bin/python3.7
PackageArchitecture: all
ProcCmdline: /usr/bin/python3 /usr/bin/software-properties-gtk --open-tab 2 --toplevel 67108867
ProcCwd: /home/edwin
ProcEnviron:
 LANG=en_US.UTF-8
 PATH=(custom, no user)
 SHELL=/bin/bash
 XDG_RUNTIME_DIR=<set>
Python3Details: /usr/bin/python3.7, Python 3.7.5, python3-minimal, 3.7.5-1
PythonArgs: ['/usr/bin/software-properties-gtk', '--open-tab', '2', '--toplevel', '67108867']
PythonDetails: /usr/bin/python2.7, Python 2.7.17rc1, python-minimal, 2.7.17-1
SourcePackage: software-properties
Title: software-properties-gtk crashed with TypeError in new_init(): could not convert value for property `transient_for' from DialogCacheOutdated to GtkWindow
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin lxd plugdev sambashare sudo
mtime.conffile..etc.apport.crashdb.conf: 2019-11-24T17:17:29.098099

[Seija K. (rose128)]

     I attempted to backtrace using gdb on the Software Updater when the Software properties window crashed. I am uploading this in case it is related.