1945771 - Perma browser/base/content/test/performance/browser_startup_flicker.js | unexpected changed rect: ({x1:221, x2:236, y1:56, y2:71, w:16, h:16}), window width: 1280 - when Gecko 136 merges to beta on 2025-02-03

Status: RESOLVED DUPLICATE of bug 1945698

(Toolkit :: Performance Monitoring, defect)

Description

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

With the patch from bug 1945167 applied, the following flicker failure gets reported on debug:

Central-as-beta-simulation

How to run these simulations

Failure log

[task 2025-02-03T11:03:17.938Z] 11:03:17     INFO - TEST-START | browser/base/content/test/performance/browser_startup_flicker.js
[task 2025-02-03T11:03:18.808Z] 11:03:18     INFO - TEST-INFO | started process screentopng
[task 2025-02-03T11:03:18.951Z] 11:03:18     INFO - TEST-INFO | screentopng: exit 0
[task 2025-02-03T11:03:18.952Z] 11:03:18     INFO - Buffered messages logged at 11:03:17
[task 2025-02-03T11:03:18.952Z] 11:03:18     INFO - Entering test bound 
[task 2025-02-03T11:03:18.953Z] 11:03:18     INFO - Buffered messages logged at 11:03:18
[task 2025-02-03T11:03:18.954Z] 11:03:18     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_flicker.js | Should have captured some frames. - 
[task 2025-02-03T11:03:18.954Z] 11:03:18     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_flicker.js | bug 1445161 - the window should be focused at first paint, [{x1:0, x2:1279, y1:0, y2:43, w:1280, h:44}, {x1:245, x2:444, y1:50, y2:77, w:200, h:28}, {x1:1176, x2:1191, y1:56, y2:71, w:16, h:16}, {x1:1214, x2:1226, y1:56, y2:71, w:13, h:16}, {x1:89, x2:102, y1:57, y2:70, w:14, h:14}, {x1:222, x2:235, y1:57, y2:70, w:14, h:14}, {x1:17, x2:30, y1:58, y2:70, w:14, h:13}, {x1:53, x2:66, y1:58, y2:70, w:14, h:13}, {x1:1141, x2:1154, y1:58, y2:70, w:14, h:13}, {x1:1250, x2:1261, y1:59, y2:68, w:12, h:10}] - 
[task 2025-02-03T11:03:18.954Z] 11:03:18     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_flicker.js | bug 1445161 - the window should be focused at first paint, [] - 
[task 2025-02-03T11:03:18.955Z] 11:03:18     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_flicker.js | bug 1445161 - the window should be focused at first paint, [] - 
[task 2025-02-03T11:03:18.955Z] 11:03:18     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_flicker.js | bug 1445161 - the window should be focused at first paint, [] - 
[task 2025-02-03T11:03:18.955Z] 11:03:18     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_flicker.js | bug 1445161 - the window should be focused at first paint, [] - 
[task 2025-02-03T11:03:18.956Z] 11:03:18     INFO - TEST-PASS | browser/base/content/test/performance/browser_startup_flicker.js | bug 1445161 - the window should be focused at first paint, [] - 
[task 2025-02-03T11:03:18.956Z] 11:03:18     INFO - Buffered messages finished
[task 2025-02-03T11:03:18.957Z] 11:03:18     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/performance/browser_startup_flicker.js | unexpected changed rect: ({x1:221, x2:236, y1:56, y2:71, w:16, h:16}), window width: 1280 - 
[task 2025-02-03T11:03:18.957Z] 11:03:18     INFO - Stack trace:
[task 2025-02-03T11:03:18.957Z] 11:03:18     INFO - chrome://mochikit/content/browser-test.js:test_ok:1599
[task 2025-02-03T11:03:18.957Z] 11:03:18     INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_startup_flicker.js:rects<:54
[task 2025-02-03T11:03:18.957Z] 11:03:18     INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_startup_flicker.js:null:37

base64 encoded screenshots in the log.