Crash installing packages using debconf

[errors.ubuntu.com bug bridge]

[Impact]
Installing .deb package via PackageKit (e.g. using GNOME Software) don't work reliably when the packages use debconf. This is due to a faulty implementation of debconf handling in PackageKit.

[Test Case]
1. Download opera deb file from opera.com
2. Run the file to launch gnome-software
3. Install it
4. Proceed with the debconf prompt

Expected result:
A debconf dialog appears asking if you want to "update Opera with the rest of the system?". The dialog closes when completed and the package is installed.

Actual result:
The dialog shows, but never closes and becomes unresponsive. Force closing the dialog causes a crash.

[Regression Potential]
The change is quite large, so there is a reasonable chance of introducing new bugs in debconf handling. However, the existing code has some obviously wrong codepaths, so the new code is probably a lower risk than the existing code.

Crash reports:
https://errors.ubuntu.com/problem/f111546905209e7288c7f8ba5f8f19eea4d97bad

[Sebastien Bacher (seb128)]

That's a bit similar to bug #1724248, doesn't have many reports at the moment so setting as low

[Launchpad Janitor (janitor)]

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

[Sebastien Bacher (seb128)]

Robert, that's one of the top 17.10 errors, could you have a look?

[Jean-Baptiste Lallement (jibel)]

Top gnome-software error on bionic.

[Jean-Baptiste Lallement (jibel)]

it's similar to bug 1724247 and 2 report mention that it happened during installation of opera and wireshark which both show debconf prompts during installation.

[Will Cooke (willcooke)]

Possibly the same as: https://bugs.launchpad.net/ubuntu/+source/gnome-software/+bug/1724247

[Launchpad Janitor (janitor)]

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

[Robert Ancell (robert-ancell)]

Seems to be an issue in PackageKit - it doesn't unregister callbacks when the PkClientHelper object is finalized.

[Robert Ancell (robert-ancell)]

https://github.com/hughsie/PackageKit/pull/250

[Robert Ancell (robert-ancell)]

I can still reproduce after the above change, but that does fix some possibly related errors.

I can reproduce reliably, as it seems to be due to the debconf-communicate window not closing for some reason. The shell prompts you to force quit, and clicking that is causing packagekit-glib (and thus gnome-software) to crash.

[Robert Ancell (robert-ancell)]

More complex changes:
https://github.com/hughsie/PackageKit/pull/252

[Łukasz Zemczak (sil2100)]

Since the proposed changes are quite big and seem a bit intrusive, I would appreciate a Regression Potential analysis as per our SRU guidelines. I would like to know where we could expect regressions after this change lands in the stable series.

Also, even though this does seem to be like a frequently-seen crash for both bionic and artful, I wouldn't want to jam it into the stable series too hastily. I see the second PackageKit pull request has not yet been approved by upstream - could we get someone reviewing it and merging before we proceed? Normally I'd also wait for cosmic to migrate, but I actually see we're only blocked on the armhf tests not being run - so it seems to be fine so far.

[Launchpad Janitor (janitor)]

This bug was fixed in the package packagekit - 1.1.10-1ubuntu1

---------------
packagekit (1.1.10-1ubuntu1) cosmic; urgency=medium

  * debian/patches/0001-De-register-callbacks-on-PkClientHelper-finalize.patch:
  * debian/patches/0001-Fix-issues-with-debconf-helper-not-working.patch:
    - Fix debconf interaction (LP: #1722185)

 -- Robert Ancell <email address hidden> Mon, 21 May 2018 15:13:02 +1200

[Robie Basak (racb)]

> I see the second PackageKit pull request has not yet been approved by upstream - could we get someone reviewing it and merging before we proceed?

I think the SRU remains blocked on this question?

[Robert Ancell (robert-ancell)]

Merged upstream

[Steve Langasek (vorlon)]

Hello errors.ubuntu.com, or anyone else affected,

Accepted packagekit into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/packagekit/1.1.9-1ubuntu2.18.04.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Jean-Baptiste Lallement (jibel)]

SRU verification for Bionic:
I have reproduced the problem with packagekit 1.1.9-1ubuntu2 in bionic and have verified that the version of packagekit 1.1.9-1ubuntu2.18.04.1 in -proposed fixes the issue.

Marking as verification-done

[Brian Murray (brian-murray)]

Were packages other than opera and which use debconf tested to ensure there are no regressions?

[Julian Andres Klode (juliank)]

I think I played with some more, but essentially the current code is just severely broken, even if there are regressions somewhere, they'd be less severe than the current state.

[Launchpad Janitor (janitor)]

This bug was fixed in the package packagekit - 1.1.9-1ubuntu2.18.04.1

---------------
packagekit (1.1.9-1ubuntu2.18.04.1) bionic; urgency=medium

  * debian/patches/0001-De-register-callbacks-on-PkClientHelper-finalize.patch:
  * debian/patches/0001-Fix-issues-with-debconf-helper-not-working.patch:
    - Fix debconf interaction (LP: #1722185)

 -- Robert Ancell <email address hidden> Mon, 21 May 2018 14:39:14 +1200

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for packagekit has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.