ubuntu-release-upgrader crashed with AttributeError: 'NoneType' object has no attribute 'group'

[errors.ubuntu.com bug bridge]

The Ubuntu Error Tracker has been receiving reports about a problem regarding ubuntu-release-upgrader. This problem was most recently seen with package version 1:19.04.16.2, the problem page at https://errors.ubuntu.com/problem/8a4265cf9ce24a669031fe6f29198fa4c9c8f562 contains more details, including versions of packages affected, stacktrace or traceback, and individual crash reports.
If you do not have access to the Ubuntu Error Tracker and are a software developer, you can request it at http://forms.canonical.com/reports/.

[Brian Murray (brian-murray)]

Here's the Traceback:

Traceback (most recent call last):
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/disco", line 8, in <module>
    sys.exit(main())
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeMain.py", line 238, in main
    if app.run():
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeController.py", line 2086, in run
    return self.fullUpgrade()
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeController.py", line 1995, in fullUpgrade
    if not self.askDistUpgrade():
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeController.py", line 1154, in askDistUpgrade
    changes = self.calcDistUpgrade()
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeController.py", line 1117, in calcDistUpgrade
    if not self.cache.distUpgrade(self._view, self.serverMode, self._partialUpgrade):
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeCache.py", line 241, in wrapper
    res = f(*args, **kwargs)
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeCache.py", line 653, in distUpgrade
    self.post_upgrade_rule()
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeCache.py", line 492, in post_upgrade_rule
    self.quirks.run("PostDistUpgradeCache")
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeQuirks.py", line 84, in run
    func()
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeQuirks.py", line 152, in PostDistUpgradeCache
    self._install_linux_metapackage()
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeQuirks.py", line 728, in _install_linux_metapackage
    linux_metapackage = self._get_linux_metapackage(cache, False)
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeQuirks.py", line 698, in _get_linux_metapackage
    version):
  File "/tmp/ubuntu-release-upgrader-hpf_vq3m/DistUpgrade/DistUpgradeQuirks.py", line 669, in _is_greater_than
    term2 = '%s-%s' % (match2.group(1),
AttributeError: 'NoneType' object has no attribute 'group'