update-manager crashes when started

[Giacomo Massa]

On Ubuntu 22.04.4 LTS the Update Manager crashes when started either from launcher or from terminal with the following traceback:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/UpdateManager/backend/InstallBackendAptdaemon.py", line 448, in _on_finished
    self._action_done(action,
  File "/usr/lib/python3/dist-packages/UpdateManager/backend/__init__.py", line 365, in _action_done
    self.window_main.start_available()
  File "/usr/lib/python3/dist-packages/UpdateManager/UpdateManager.py", line 241, in start_available
    self.refresh_cache()
  File "/usr/lib/python3/dist-packages/UpdateManager/UpdateManager.py", line 459, in refresh_cache
    self._get_ua_security_status()
  File "/usr/lib/python3/dist-packages/UpdateManager/UpdateManager.py", line 285, in _get_ua_security_status
    s = json.load(p.stdout)
  File "/usr/lib/python3.10/json/__init__.py", line 293, in load
    return loads(fp.read(),
  File "/usr/lib/python3.10/json/__init__.py", line 346, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python3.10/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python3.10/json/decoder.py", line 355, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

System: Ubuntu 22.04.4 LTS

Package version: update-manager: version 1:22.04.19

What is expected: for the program to run without crashing.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: ubuntu-advantage-tools 31.2~22.04
ProcVersionSignature: Ubuntu 6.1.0-1035.35-oem 6.1.78
Uname: Linux 6.1.0-1035-oem x86_64
ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Sun Mar 17 21:06:44 2024
DistributionChannelDescriptor:
 # This is the distribution channel descriptor for the OEM CDs
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-jammy-amd64-20220504-33
InstallationDate: Installed on 2024-01-27 (50 days ago)
InstallationMedia: Ubuntu 22.04 LTS "Jammy Jellyfish" - somerville-jammy-amd64-20220504-33
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=it_IT.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-advantage-tools
UpgradeStatus: No upgrade log present (probably fresh install)
apparmor_logs.txt:

cloud-id.txt-error: Invalid command specified 'cloud-id'.
livepatch-status.txt-error: Failed running command '/snap/bin/canonical-livepatch status' [exit(1)]. Message: error executing status: open /var/snap/canonical-livepatch/264/livepatchd.err: permission denied
uaclient.conf:
 contract_url: https://contracts.canonical.com
 log_level: debug

[Alberto Contreras (aciba)]

Thanks, Giacomo Massa, for reporting this issue.

This traceback is the same as in https://bugs.launchpad.net/ubuntu/+source/ubuntu-advantage-tools/+bug/2058133 .

Could you please paste the output of `pro security-status --format=json`? See, https://bugs.launchpad.net/ubuntu/+source/ubuntu-advantage-tools/+bug/2058133/comments/2 .