Public bug reported: If the upgrader fails its url_downloadable check from http://archive.ubuntu.com (while apt update succeeds), it will prompt for the default sources to be restored. If yes is selected, an AttributeError will be raised as the _addDefaultSources() function attempts to set a property (suites) without a setter.
Example: Reading cache Checking package manager Reading package lists... 0% Reading package lists... 100% Reading package lists... Done Building dependency tree... 0% Building dependency tree... 0% Building dependency tree... 50% Building dependency tree... 50% Building dependency tree... Done Reading state information... 0% Reading state information... 0% Reading state information... Done 0% [Working] 0% [Working] 0% [Connecting to archive.ubuntu.com] 0% [Connecting to archive.ubuntu.com] 0% [Connecting to archive.ubuntu.com (104.20.28.246)] 0% [Connecting to archive.ubuntu.com (104.20.28.246)] 0% [Connecting to archive.ubuntu.com (104.20.28.246)] 0% [Connecting to archive.ubuntu.com (104.20.28.246)] 0% [Connected to archive.ubuntu.com (104.20.28.246)] 0% [Connected to archive.ubuntu.com (104.20.28.246)] 0% [Waiting for headers] [Connecting to security.ubuntu.com] 0% [Waiting for headers] [Connecting to security.ubuntu.com] 0% [Waiting for headers] 0% [Waiting for headers] 0% [Waiting for headers] [Connected to security.ubuntu.com (172.66.152.176)] 0% [Waiting for headers] [Connected to security.ubuntu.com (172.66.152.176)] 0% [Waiting for headers] [Waiting for headers] 0% [Waiting for headers] [Waiting for headers] Hit http://archive.ubuntu.com/ubuntu noble InRelease 0% [Waiting for headers] 0% [Waiting for headers] 0% [Waiting for headers] [Waiting for headers] 0% [Waiting for headers] [Waiting for headers] Hit http://security.ubuntu.com/ubuntu noble-security InRelease 0% [Waiting for headers] 0% [Waiting for headers] 87% [Waiting for headers] 87% [Waiting for headers] 87% [Waiting for headers] 87% [Waiting for headers] 95% [Waiting for headers] 95% [Waiting for headers] Hit http://archive.ubuntu.com/ubuntu noble-updates InRelease 95% [Working] 95% [Working] 95% [Waiting for headers] 95% [Waiting for headers] 97% [Waiting for headers] 97% [Waiting for headers] Hit http://archive.ubuntu.com/ubuntu noble-backports InRelease 97% [Working] 97% [Working] 97% [Working] 97% [Working] 99% [Working] 99% [Working] Fetched 0 B in 0s (0 B/s) Reading package lists... 0% Reading package lists... 100% Reading package lists... Done Building dependency tree... 0% Building dependency tree... 0% Building dependency tree... 50% Building dependency tree... 50% Building dependency tree... Done Reading state information... 0% Reading state information... 0% Reading state information... Done No snaps are installed yet. Try 'snap install hello-world'. Checking for installed snaps Calculating snap size requirements Updating repository information Required apt sources are missing This is probably because one or more of the following mirrors are out-of-date or unreachable: http://archive.ubuntu.com/ubuntu Would you like to continue the upgrade using default sources? If you select 'No', the upgrade will be aborted. Continue [yN] y Traceback (most recent call last): File "/tmp/ubuntu-release-upgrader-7d18weqn/resolute", line 8, in <module> sys.exit(main()) ^^^^^^ File "/tmp/ubuntu-release-upgrader-7d18weqn/DistUpgrade/DistUpgradeMain.py", line 235, in main if app.run(): ^^^^^^^^^ File "/tmp/ubuntu-release-upgrader-7d18weqn/DistUpgrade/DistUpgradeController.py", line 2014, in run return self.fullUpgrade() ^^^^^^^^^^^^^^^^^^ File "/tmp/ubuntu-release-upgrader-7d18weqn/DistUpgrade/DistUpgradeController.py", line 1876, in fullUpgrade if not self.updateDeb822Sources(): ^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/tmp/ubuntu-release-upgrader-7d18weqn/DistUpgrade/DistUpgradeController.py", line 1061, in updateDeb822Sources if not self.rewriteDeb822Sources(): ^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/tmp/ubuntu-release-upgrader-7d18weqn/DistUpgrade/DistUpgradeController.py", line 1048, in rewriteDeb822Sources self._addDefaultSources() File "/tmp/ubuntu-release-upgrader-7d18weqn/DistUpgrade/DistUpgradeController.py", line 805, in _addDefaultSources e.suites = sorted([self.toDist, self.toDist + '-updates'], ^^^^^^^^ AttributeError: property 'suites' of 'ExplodedDeb822SourceEntry' object has no setter *** Send problem report to the developers? After the problem report has been sent, please fill out the form in the automatically opened web browser. What would you like to do? Your options are: S: Send report (39.4 KB) V: View report K: Keep report file for sending later or copying to somewhere else I: Cancel and ignore future crashes of this program version C: Cancel Please choose (S/V/K/I/C): c === Command terminated with exit status 1 (Wed May 6 15:45:29 2026) === ** Affects: ubuntu-release-upgrader (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2151640 Title: Falling back to default sources raises AttributeError if archive.ubuntu.com is unreachable To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/2151640/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
