Problem: 'App' object is not iterable - Update from App fails

[mroessler]

Problem

Update an App or upgrade UCS itself including the Apps show an error that looks like:

Starting app upgrade                                   Traceback in univention-upgrade:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/univention/updater/scripts/upgrade.py", line 430, in do_update
    update_available = performUpdate(options, checkForUpdates=options.check, silent=False)
  File "/usr/lib/python3/dist-packages/univention/updater/scripts/upgrade.py", line 139, in performUpdate
    if func(options, checkForUpdates, silent):
  File "/usr/lib/python3/dist-packages/univention/updater/scripts/upgrade.py", line 314, in do_app_updates
    pwdfile=options.pwdfile.name if options.pwdfile else None,
  File "/usr/lib/python3/dist-packages/univention/appcenter/actions/__init__.py", line 167, in call_safe
    return cls.call(**kwargs)
  File "/usr/lib/python3/dist-packages/univention/appcenter/actions/__init__.py", line 175, in call
    return obj.call_with_namespace(namespace)
  File "/usr/lib/python3/dist-packages/univention/appcenter/actions/__init__.py", line 181, in call_with_namespace
    result = self.main(namespace)
  File "/usr/lib/python3/dist-packages/univention/appcenter/actions/upgrade.py", line 75, in main
    for app in apps:
TypeError: 'App' object is not iterable

Solution

The “Nextcloud” and “UCS@school” App was chosen because they are most often affected. This are still examples and this issue could be take place for other Apps as well.

Either try to manually install the App again:

For Nextcloud
univention-app install nextcloud

For UCS@school
univention-app install ucsschool

Or to upgrade the App again:

For Nextcloud
univention-app upgrade nextcloud

For UCS@school
univention-app upgrade ucsschool

If both not work try to uninstall and re-install again:

It could be necessary to execute the install of the App twice

For Nextcloud
univention-app remove nextcloud
univention-app install nextcloud
univention-app install nextcloud

For UCS@school
univention-app remove ucsschool
univention-app install ucsschool
univention-app install ucsschool

(After the steps worked you can re-run your univention-upgrade command, if you did ran an UCS upgrade before running into this situation.)