Endless "Cache Refresh" on Software Update settings change

[Plamen]

After reapplying some of the checkboxes under "Software & Updates" -> "Other Software" after distro upgrade, a window with title "Cache Refresh" pops and never disappears. (check screenshot bellow)

> lsb_release -rd
Description: Ubuntu 20.04.1 LTS
Release: 20.04

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: software-properties-gtk 0.98.9.2
ProcVersionSignature: Ubuntu 5.4.0-52.57-generic 5.4.65
Uname: Linux 5.4.0-52-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27.11
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: GNOME
Date: Mon Nov 9 01:55:13 2020
ExecutablePath: /usr/bin/software-properties-gtk
InstallationDate: Installed on 2015-06-17 (1971 days ago)
InstallationMedia: Ubuntu-GNOME 15.04 "Vivid Vervet" - Release amd64 (20150422)
InterpreterPath: /usr/bin/python3.8
PackageArchitecture: all
Python3Details: /usr/bin/python3.8, Python 3.8.5, python3-minimal, 3.8.2-0ubuntu2
PythonDetails: /usr/bin/python2.7, Python 2.7.18, python-is-python2, 2.7.17-4
SourcePackage: software-properties
UpgradeStatus: Upgraded to focal on 2020-09-29 (40 days ago)

[Sebastien Bacher (seb128)]

Thank you for your bug report, was it a one time issue of does it keep doing it? Could you include the 'journalctl -b <n>' log from a session where you hit the issue?

[Plamen (plamen-shkodrov)]

It got stranger this time. Now while the "Cache Refresh" window was hanging the software list with things to update popped (new image attached). Updated the listed programs and closed it and the Cache Refresh was still there.

How can I retrieve the number for the command you sent. The n in 'journalctl -b <n>'

[Sebastien Bacher (seb128)]

<n> is the number of restart since the issue, if you managed to trigger it in your current session it's 0

[Plamen (plamen-shkodrov)]

I`m unable to reproduce it anymore. Except in the case for the openvpn source from this address: http://build.openvpn.net/debian/openvpn/stable

Managed to see the error when opening the software update from terminal via `software-properties-gtk` -> in the attached file and below.

Apparently there is some issue with the openvpn repo and the error handling in such cases is failing somehow:

```
$ software-properties-gtk
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/softwareproperties/gtk/DialogCacheOutdated.py", line 86, in on_pktask_finish
    results = self._pktask.generic_finish(result)
gi.repository.GLib.Error: pk-client-error-quark: W: GPG error: http://build.openvpn.net/debian/openvpn/stable bionic InRelease: The following signatures were invalid: EXPKEYSIG 8E6DA8B4E158C569 Samuli Seppänen (OpenVPN Technologies, Inc) <email address hidden>
E: The repository 'http://build.openvpn.net/debian/openvpn/stable bionic InRelease' is not signed.
W: Updating from such a repository can't be done securely, and is therefore disabled by default.
W: See apt-secure(8) manpage for repository creation and user configuration details.
E: http://build.openvpn.net/debian/openvpn/stable bionic InRelease is not (yet) available (The following signatures were invalid: EXPKEYSIG 8E6DA8B4E158C569 Samuli Seppänen (OpenVPN Technologies, Inc) <email address hidden>)
 (319)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/softwareproperties/gtk/DialogCacheOutdated.py", line 88, in on_pktask_finish
    dialog = Gtk.MessageDialog(self, 0, Gtk.MessageType.ERROR,
  File "/usr/lib/python3/dist-packages/gi/overrides/__init__.py", line 319, in new_init
    return super_init_func(self, **new_kwargs)
  File "/usr/lib/python3/dist-packages/gi/overrides/Gtk.py", line 577, in __init__
    self._init(*args, **new_kwargs)
  File "/usr/lib/python3/dist-packages/gi/overrides/__init__.py", line 319, in new_init
    return super_init_func(self, **new_kwargs)
  File "/usr/lib/python3/dist-packages/gi/overrides/Gtk.py", line 523, in __init__
    _window_init(self, *args, **kwargs)
  File "/usr/lib/python3/dist-packages/gi/overrides/__init__.py", line 319, in new_init
    return super_init_func(self, **new_kwargs)
TypeError: could not convert value for property `transient_for' from DialogCacheOutdated to GtkWindow
```

[Plamen (plamen-shkodrov)]

This is the log after `journalctl -b 0` if its still needed.
```
$ journalctl -b 0
-- Logs begin at Wed 2020-11-18 15:14:32 EET, end at Wed 2020-12-30 02:53:25 EET. --
дек 30 02:38:23 desktop kernel: Linux version 5.4.0-58-generic (buildd@lcy01-amd64-004) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #64-Ubuntu SMP >
дек 30 02:38:23 desktop kernel: Command line: BOOT_IMAGE=/boot/vmlinuz-5.4.0-58-generic root=UUID=db78bb87-80bc-4175-935a-18f69d5c471d ro quiet splash
дек 30 02:38:23 desktop kernel: KERNEL supported cpus:
дек 30 02:38:23 desktop kernel: Intel GenuineIntel
дек 30 02:38:23 desktop kernel: AMD AuthenticAMD
дек 30 02:38:23 desktop kernel: Hygon HygonGenuine
дек 30 02:38:23 desktop kernel: Centaur CentaurHauls
дек 30 02:38:23 desktop kernel: zhaoxin Shanghai
дек 30 02:38:23 desktop kernel: x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers'
дек 30 02:38:23 desktop kernel: x86/fpu: Supporting XSAVE feature 0x002: 'SSE registers'
дек 30 02:38:23 desktop kernel: x86/fpu: Supporting XSAVE feature 0x004: 'AVX registers'
дек 30 02:38:23 desktop kernel: x86/fpu: xstate_offset[2]: 576, xstate_sizes[2]: 256
дек 30 02:38:23 desktop kernel: x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'compacted' format.
дек 30 02:38:23 desktop kernel: BIOS-provided physical RAM map:
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x0000000000000000-0x000000000009d3ff] usable
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x000000000009d400-0x000000000009ffff] reserved
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x0000000000100000-0x0000000009d01fff] usable
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x0000000009d02000-0x0000000009ffffff] reserved
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x000000000a000000-0x000000000a1fffff] usable
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x000000000a200000-0x000000000a20bfff] ACPI NVS
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x000000000a20c000-0x00000000da1d6fff] usable
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x00000000da1d7000-0x00000000db6d5fff] reserved
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x00000000db6d6000-0x00000000db857fff] usable
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x00000000db858000-0x00000000dbc6bfff] ACPI NVS
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x00000000dbc6c000-0x00000000dc9defff] reserved
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x00000000dc9df000-0x00000000deffffff] usable
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x00000000df000000-0x00000000dfffffff] reserved
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x00000000f8000000-0x00000000fbffffff] reserved
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x00000000fd000000-0x00000000ffffffff] reserved
дек 30 02:38:23 desktop kernel: BIOS-e820: [mem 0x0000000100000000-0x000000081f37ffff] usable
дек 30 02:38:23 desktop kernel: NX (Execute Disable) protection: active
дек 30 02:38:23 desktop kernel: SMBIOS 3.2.1 present.
дек 30 02:38:23 desktop kernel: DMI: To Be Filled By O.E.M. To Be Filled By O.E.M./X570 Phantom Gaming ...

[Launchpad Janitor (janitor)]

[Expired for software-properties (Ubuntu) because there has been no activity for 60 days.]