Every cycle python-apt breaks until updated for the new distro codename

[joelw135]

The problem is currently happening in hirsute (fixed with the python-apt in proposed, software-properties fails to start due a python-apt error

  File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 605, in reload_sourceslist
    self.distro.get_sources(self.sourceslist)
  File "/usr/lib/python3/dist-packages/aptsources/distro.py", line 91, in get_sources
    raise NoDistroTemplateException(
aptsources.distro.NoDistroTemplateException: Error: could not find a distribution template for Ubuntu/hirsute

Could we try to handle the missing codename in a way that doesn't make python-apt users blow up every cycle until we play catching up?

[Norbert (nrbrtx)]

Please run `apport-collect 1902538` on this system.

[joelw135 (joel-waxman)]

@Norbert I ran apport-collect 1902538 but it said no more information added.

[Norbert (nrbrtx)]

Launching from the terminal gives the following output:

```
$ software-properties-gtk
Traceback (most recent call last):
  File "/usr/bin/software-properties-gtk", line 100, in <module>
    app = SoftwarePropertiesGtk(datadir=options.data_dir, options=options, file=file)
  File "/usr/lib/python3/dist-packages/softwareproperties/gtk/SoftwarePropertiesGtk.py", line 154, in __init__
    SoftwareProperties.__init__(self, options=options, datadir=datadir)
  File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 111, in __init__
    self.reload_sourceslist()
  File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 605, in reload_sourceslist
    self.distro.get_sources(self.sourceslist)
  File "/usr/lib/python3/dist-packages/aptsources/distro.py", line 91, in get_sources
    raise NoDistroTemplateException(
aptsources.distro.NoDistroTemplateException: Error: could not find a distribution template for Ubuntu/hirsute

```

[joelw135 (joel-waxman)]

@Norber Hopefully this can be resolved soon. Thanks.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sebastien Bacher (seb128)]

The issue should be fixed with this update

https://launchpad.net/ubuntu/+source/python-apt/2.1.3ubuntu3

it does sound like we should do better than having software-properties bail out every start of cycle until python-apt is updated, I'm going to repurpose the bug for that issue

[corrado venturini (corradoventu)]

Same problem on Ubuntu installed from Ubuntu 21.04 "Hirsute Hippo" - Alpha amd64 (20201104)

[Julian Andres Klode (juliank)]

Dupe of 1727470. FWIW, python-apt 2.1.15 does not hard code codenames anymore, so won't have this issue.