Software&Updates doesn't launch (Ubuntu 22.04)

Question

I have a problem with Software&Updates launching (Ubuntu 22.04).

Syslog:

Aug 22 11:07:03 maskalev-Aspire-A514-54 systemd[3327]: Started Application launched by gnome-shell.
Aug 22 11:07:04 maskalev-Aspire-A514-54 dbus-daemon[817]: [system] Activating service name='com.ubuntu.SoftwareProperties' requested by ':1.190' (uid=1000 pid=14929 comm="/usr/bin/python3 /usr/bin/software
-properties-gtk " label="unconfined") (using servicehelper)
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]: Traceback (most recent call last):
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:   File "/lib/python3/dist-packages/launchpadlib/launchpad.py", line 34, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:     from httplib2 import proxy_info_from_environment
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:   File "/lib/python3/dist-packages/httplib2/__init__.py", line 52, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:     from . import auth
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:   File "/lib/python3/dist-packages/httplib2/auth.py", line 4, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:     import pyparsing as pp
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]: ModuleNotFoundError: No module named 'pyparsing'
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]: During handling of the above exception, another exception occurred:
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]: Traceback (most recent call last):
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:   File "/usr/lib/software-properties/software-properties-dbus", line 29, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:     from softwareproperties.dbus.SoftwarePropertiesDBus import (
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:   File "/lib/python3/dist-packages/softwareproperties/dbus/SoftwarePropertiesDBus.py", line 32, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:     from softwareproperties.SoftwareProperties import SoftwareProperties
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:   File "/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 64, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:     from softwareproperties.shortcuts import shortcut_handler
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:   File "/lib/python3/dist-packages/softwareproperties/shortcuts.py", line 23, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:     from softwareproperties.ppa import PPAShortcutHandler
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:   File "/lib/python3/dist-packages/softwareproperties/ppa.py", line 25, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:     from launchpadlib.launchpad import Launchpad
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:   File "/lib/python3/dist-packages/launchpadlib/launchpad.py", line 36, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:     from httplib2 import ProxyInfo
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:   File "/lib/python3/dist-packages/httplib2/__init__.py", line 52, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:     from . import auth
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:   File "/lib/python3/dist-packages/httplib2/auth.py", line 4, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]:     import pyparsing as pp
Aug 22 11:07:04 maskalev-Aspire-A514-54 com.ubuntu.SoftwareProperties[14940]: ModuleNotFoundError: No module named 'pyparsing'
Aug 22 11:07:04 maskalev-Aspire-A514-54 dbus-daemon[817]: [system] Activated service 'com.ubuntu.SoftwareProperties' failed: Launch helper exited with unknown return code 1
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]: Traceback (most recent call last):
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:   File "/usr/lib/python3/dist-packages/dbus/bus.py", line 177, in activate_name_owner
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:     return self.get_name_owner(bus_name)
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:   File "/usr/lib/python3/dist-packages/dbus/bus.py", line 361, in get_name_owner
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:     return self.call_blocking(BUS_DAEMON_NAME, BUS_DAEMON_PATH,
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:   File "/usr/lib/python3/dist-packages/dbus/connection.py", line 652, in call_blocking
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:     reply_message = self.send_message_with_reply_and_block(
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NameHasNoOwner: Could not get owner of name 'com.ubuntu.SoftwareProperties': no such name
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]: During handling of the above exception, another exception occurred:
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]: Traceback (most recent call last):
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:   File "/usr/bin/software-properties-gtk", line 100, in <module>
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:     app = SoftwarePropertiesGtk(datadir=options.data_dir, options=options, file=file)
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:   File "/usr/lib/python3/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 210, in __init__
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:     proxy = bus.get_object("com.ubuntu.SoftwareProperties", "/")
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:   File "/usr/lib/python3/dist-packages/dbus/bus.py", line 241, in get_object
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:     return self.ProxyObjectClass(self, bus_name, object_path,
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:   File "/usr/lib/python3/dist-packages/dbus/proxies.py", line 250, in __init__
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:     self._named_service = conn.activate_name_owner(bus_name)
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:   File "/usr/lib/python3/dist-packages/dbus/bus.py", line 182, in activate_name_owner
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:     self.start_service_by_name(bus_name)
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:   File "/usr/lib/python3/dist-packages/dbus/bus.py", line 277, in start_service_by_name
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:     return (True, self.call_blocking(BUS_DAEMON_NAME, BUS_DAEMON_PATH,
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:   File "/usr/lib/python3/dist-packages/dbus/connection.py", line 652, in call_blocking
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]:     reply_message = self.send_message_with_reply_and_block(
Aug 22 11:07:04 maskalev-Aspire-A514-54 software-properties-gtk.desktop[14929]: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.Spawn.ChildExited: Launch helper exited with unknown return code 1

I assume that something is wrong with Python (path, version etc.)

maskalev@maskalev-Aspire-A514-54:~$ pip install pyparsing
Defaulting to user installation because normal site-packages is not writeable
Requirement already satisfied: pyparsing in ./.local/lib/python3.10/site-packages (3.0.9)
maskalev@maskalev-Aspire-A514-54:~$ python3 -c "import sys; print(sys.path)"
['', '/usr/lib/python310.zip', '/usr/lib/python3.10', '/usr/lib/python3.10/lib-dynload', '/home/maskalev/.local/lib/python3.10/site-packages', '/usr/local/lib/python3.10/dist-packages', '/usr/lib/python3/dist-packages']
maskalev@maskalev-Aspire-A514-54:~$ whereis python3
python3: /usr/bin/python3 /usr/lib/python3 /etc/python3 /usr/share/python3 /usr/share/man/man1/python3.1.gz
maskalev@maskalev-Aspire-A514-54:~$ ls /usr/bin/python*
/usr/bin/python2.7         /usr/bin/python3     /usr/bin/python3.10-config  /usr/bin/python3.11-config  /usr/bin/python3-futurize    /usr/bin/python-dotenv
/usr/bin/python2.7-config  /usr/bin/python3.10  /usr/bin/python3.11         /usr/bin/python3-config     /usr/bin/python3-pasteurize

I will be glad of any advice. I will send any additional information on request

Answer 1

Your local user installation isn't relevant to the system software. You can't use pip to install system-wide python packages¹.

Since Ubuntu pretty certainly makes the software center depend on the python3-pyparsing package, you must have somehow removed that package (or just its contents?) without dpkg/apt noticing. The fact that you're attempting to fix this with pip gives me the hunch that you somewhere did something like sudo pip uninstall and broke your system. You will then most probably encounter more broken things down the way; it's unlikely that removing pyparsing didn't remove other crucial modules as well. Maybe you actually overwrote the python3 executable that your system uses?

You can try to fix your immediate problem with sudo apt-get reinstall python3-pyparsing, but I'm afraid with the multiple versions of python that clutter your path, and if my guess that you have mixed pip installations in to your system and thus broke it in ways that are tedious to clean up, your quickest solution might be saving your user's home and setting up Ubuntu anew. Your success might really vary, and the amount of time you invest.

---

¹This is exactly the case that I describe here and here, where pip has no idea that your system needs some specific version of some specific python module, and breaks your system.