[Bug 2151640] [NEW] Falling back to default sources raises AttributeError if archive.ubuntu.com is unreachable
Simon Johnsson
2151640 at bugs.launchpad.net
Wed May 6 15:48:32 UTC 2026
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
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=== Command terminated with exit status 1 (Wed May 6 15:45:29 2026) ===
** Affects: ubuntu-release-upgrader (Ubuntu)
Importance: Undecided
Status: New
--
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https://bugs.launchpad.net/bugs/2151640
Title:
Falling back to default sources raises AttributeError if
archive.ubuntu.com is unreachable
Status in ubuntu-release-upgrader package in Ubuntu:
New
Bug description:
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) ===
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