1835707 - [mozscreenshots] failed to create screenshot GdkPixbuf on new Wayland-enabled environment

Status: VERIFIED FIXED

(Core :: Widget: Gtk, defect)

Description

[Andrew Halberstadt [:ahal]]

We're starting to stand up tests that run in a VM with Wayland enabled. One issue is that Mochitest's screenshot on fail feature (which uses mozscreenshots via screentopng), is failing with:

[task 2023-05-26T19:35:20.744Z] 19:35:20     INFO - TEST-INFO | started process screentopng
[task 2023-05-26T19:35:20.816Z] 19:35:20     INFO -  (screentopng:15883): Gdk-CRITICAL **: 19:35:20.816: gdk_pixbuf_get_from_surface: assertion 'width > 0 && height > 0' failed
[task 2023-05-26T19:35:20.817Z] 19:35:20     INFO -  /home/ubuntu/tasks/task_168512798664919/build/tests/bin/screentopng: failed to create screenshot GdkPixbuf
[task 2023-05-26T19:35:20.823Z] 19:35:20     INFO - TEST-INFO | screentopng: exit 1

Full log:
https://treeherder.mozilla.org/logviewer?job_id=417197398&repo=try&lineNumber=8951

There's a very high chance that there's nothing wrong with mozscreenshots here and that there's an issue with how the test environment is set up. If this is the case, I'm hoping that someone knowledgeable could help point us in the right direction.

Comment 1

[Andrew Halberstadt [:ahal]]

Updating component again according to ./mach file-info bugzilla-component.

Comment 2

[Karl Tomlinson (:karlt)]

Looks like the screenshot utility is depending on GNOME Shell with Wayland.
Does the test environment have GNOME Shell?

Comment 3

[Andrew Halberstadt [:ahal]]

Good catch, I'd guess not. I also found a user reporting this error when they had GDK_BACKEND explicitly set to x11. We'll need to wait for aerickson to get back from PTO later this week.

Andrew (for when you get back), could you verify whether GNOME Shell is installed or GDK_BACKEND is set?

Comment 4

[Mike Hommey [:glandium]]

What compositor are the wayland tests using, BTW?

Comment 5

[Martin Stránský [:stransky] (ni? me)]

Andrew, where is the Wayland environment set? We need to use Gnome Shell / Mutter for testing. It can be configured to run headless and also allows to set scale factor. And provides Gnome Shell extension to get a screenshot.

Comment 6

[Martin Stránský [:stransky] (ni? me)]

Do I understand correctly that https://searchfox.org/mozilla-central/source/taskcluster/scripts/tester/test-linux.sh is used ? If so can try to update it for gnome-session.

Comment 7

[Martin Stránský [:stransky] (ni? me)]

So no, I was wrong. We don't need gnome session for that, Mutter provides such interface too:
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698

Comment 8

[Martin Stránský [:stransky] (ni? me)]

There's also python helper scrip for it: https://gitlab.gnome.org/GNOME/mutter/uploads/9a143d445398e26b0debef6d38b7b822/gnome-screen-cast.py

Comment 9

[Martin Stránský [:stransky] (ni? me)]

I see the bug too locally, will look at it.

Comment 10

[Martin Stránský [:stransky] (ni? me)]

Unfortunately Gnome 41.0 restricted access to org.gnome.Shell.Screenshot interface to internal components only:
https://gitlab.gnome.org/GNOME/gimp/-/issues/7591

But we can use gnome-screenshot utility for it.

Comment 11

[Martin Stránský [:stransky] (ni? me)]

Attachment: Bug 1835707 [Linux] Use gnome-screenshot by screentopng utility to get screenshot on Wayland r?emilio

Comment 12

[Martin Stránský [:stransky] (ni? me)]

Andrew, to get it working you need to install /usr/bin/gnome-screenshot utility, it's provided by gnome-screenshot package.

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2dee01e7126e
[Linux] Use gnome-screenshot by screentopng utility to get screenshot on Wayland r=emilio

Comment 14

[Andrew Halberstadt [:ahal]]

Comment on attachment 9336507 [details]
Bug 1835707 [Linux] Use gnome-screenshot by screentopng utility to get screenshot on Wayland r?emilio

Beta/Release Uplift Approval Request

• User impact if declined: The screentopng utility will be broken on Wayland environments, impacting the Mochitest screenshots feature, screenshots test suite and other things.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): I believe mozscreenshots is only used by test infrastructure and other extraneous tooling. I may be wrong though.
• String changes made/needed:
• Is Android affected?: No

Comment 15

[Andrew Halberstadt [:ahal]]

Comment on attachment 9336507 [details]
Bug 1835707 [Linux] Use gnome-screenshot by screentopng utility to get screenshot on Wayland r?emilio

Oh nvm, I got confused and yesterday's merge was only beta -> release. So this patch is already riding 115.

Comment 16

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/2dee01e7126e

Comment 17

[Andrew Erickson [:aerickson]]

I see gnome-screenshot available at /usr/bin/gnome-screenshot in the VM. I've VNC'ed into my test host and I can create screenshots.

Try jobs are unable to find it?

Comment 18

[Andrew Halberstadt [:ahal]]

The needinfo was a little stale and predates Martin's patch that landed two days ago. Thanks for verifying that gnome-screenshot is present. I haven't kicked off a new try run yet to test Martin's fix, but will do so shortly.

Comment 19

[Andrew Halberstadt [:ahal]]

I can confirm that the mochitest screenshots are working again:
https://firefoxci.taskcluster-artifacts.net/AZ0rfH--T9iaOrBz3GleLw/0/public/test_info/mozilla-test-fail-screenshot_bh8jwugn.png

Thanks Martin!

What compositor are the wayland tests using, BTW?

Pretty sure it's mutter, but I'll confirm.