1976229 - Intermittent TV [Tier 2] chrome://mochitests/content/browser/toolkit/components/extensions/test/browser/browser_ext_themes_pbm.js | changed preference: extensions.webextensions.uuids

Status: RESOLVED WORKSFORME

(WebExtensions :: General, defect, P5)

Description

[Treeherder Bug Filer]

Filed by: ctodea [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer?job_id=516819486&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/DkQjjMDmT0W46mX6PYs0EA/runs/0/artifacts/public/logs/live_backing.log
Reftest URL: https://hg.mozilla.org/mozilla-central/raw-file/tip/layout/tools/reftest/reftest-analyzer.xhtml#logurl=https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/DkQjjMDmT0W46mX6PYs0EA/runs/0/artifacts/public/logs/live_backing.log&only_show_unexpected=1

---

[task 2025-07-08T13:22:42.277+00:00] 13:22:42     INFO - TEST-PASS | toolkit/components/extensions/test/browser/browser_ext_themes_pbm.js | Prompt from private window should be themed dark. - [task 2025-07-08T13:22:42.278+00:00] 13:22:42     INFO - Leaving test bound test_pbm_dark_prompts
[task 2025-07-08T13:22:42.278+00:00] 13:22:42     INFO - Buffered messages finished
[task 2025-07-08T13:22:42.278+00:00] 13:22:42    ERROR - TEST-UNEXPECTED-FAIL | chrome://mochitests/content/browser/toolkit/components/extensions/test/browser/browser_ext_themes_pbm.js | changed preference: extensions.webextensions.uuids
[task 2025-07-08T13:22:42.279+00:00] 13:22:42    ERROR - TEST-UNEXPECTED-FAIL | chrome://mochitests/content/browser/toolkit/components/extensions/test/browser/browser_ext_themes_pbm.js | changed preference: extensions.pendingOperations
[task 2025-07-08T13:22:42.279+00:00] 13:22:42     INFO - GECKO(3949) | MEMORY STAT vsizeMaxContiguous not supported in this build configuration.
[task 2025-07-08T13:22:42.279+00:00] 13:22:42     INFO - GECKO(3949) | MEMORY STAT | vsize 45941MB | residentFast 494MB | heapAllocated 220MB
[task 2025-07-08T13:22:42.280+00:00] 13:22:42     INFO - TEST-OK | toolkit/components/extensions/test/browser/browser_ext_themes_pbm.js | took 7853ms

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

:nate, since you are the author of the regressor, bug 1968719, could you take a look?

For more information, please visit BugBot documentation.

Comment 2

[Nate Gross]

I don't think my changes are causing this intermittent failure (all tests are passing when I run them and the failure messages don't seem to be related to the specific code I touched). However, this is my first contribution here so I'd like to make sure. :robwu - when you have a chance could you please confirm? Thanks!

Comment 3

[Rob Wu [:robwu]]

This is a pre-existing issue and not something you need to worry about.
The failure is a TV job, which you can reproduce locally by running the test with the --verify flag.

The specific cause of the failure is that the test loads themes that haven't been seen before the test execution, and that causes an extension UUID to be allocated and never cleaned up. Example of logic that would trigger the allocation of an extension UUID: https://searchfox.org/mozilla-central/rev/584b344830aa2558985675b99aaadbb915402caa/toolkit/components/extensions/test/browser/browser_ext_themes_pbm.js#119-120

This recently started to result in TV failures because I added support for detecting unexpected preference changes in bug 1816549. The failure does not result in a backout of the patch that triggers the TV job, because it is a tier 2 job (see tiers). There is an effort to clean this up (bug 1975980) as a preparation to make it a tier 1 job.

If you want to reproduce this failure locally:

./mach test toolkit/components/extensions/test/browser/browser_ext_themes_pbm.js --verify

This specific issue (preferences not getting cleaned up) can be detected with:

./mach test toolkit/components/extensions/test/browser/browser_ext_themes_pbm.js --compare-preferences

(optional: add the --headless flag so you can do something else while the test is running)

Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

This bug has been marked as a regression. Setting status flag for Nightly to affected.

Comment 5

[Florian Quèze [:florian]]

In bug 1978278 I made TV jobs no longer fail for preference changes, so the failure in this bug will no longer be reported.