updating our infrastructure/tooling to fix bugs/features we have a new worker which is responsible for accepting the tests to run and launching the mozharness/test script to run the tests. The main difference in the new worker is that we login as an actual user instead of simulating it with runas and mapping directories. While doing this we find that browser_panelUINotifications_multiWindow.js is failing for us consistently: https://treeherder.mozilla.org/#/jobs?repo=try&revision=85b4ef4fa06f4a75d9b50f8a3de2a3ecab3f7afd&filter-searchStr=10-64%20browser-chrome looking at a debug log [1]: 22:06:58 INFO - 727 INFO TEST-START | browser/components/customizableui/test/browser_panelUINotifications_multiWindow.js 22:06:58 INFO - GECKO(1112) | ++DOCSHELL 000001DBB1D62000 == 2 [pid = 7468] [id = {e1c0cb68-dec2-46c2-8d5a-b5a7fba2941e}] 22:06:58 INFO - GECKO(1112) | ++DOMWINDOW == 4 (000001DBB1B1C800) [pid = 7468] [serial = 36] [outer = 0000000000000000] 22:06:58 INFO - GECKO(1112) | ++DOMWINDOW == 5 (000001DBB277F400) [pid = 7468] [serial = 37] [outer = 000001DBB1B1C800] 22:06:58 INFO - GECKO(1112) | ++DOMWINDOW == 6 (000001DBB2780C00) [pid = 7468] [serial = 38] [outer = 000001DBB1B1C800] 22:06:58 INFO - GECKO(1112) | ++DOCSHELL 000001D9413CE000 == 19 [pid = 1112] [id = {dd12a5f3-d225-4451-898b-7aac88385405}] 22:06:58 INFO - GECKO(1112) | ++DOMWINDOW == 48 (000001D939625400) [pid = 1112] [serial = 300] [outer = 0000000000000000] 22:06:58 INFO - GECKO(1112) | ++DOMWINDOW == 49 (000001D93A09A400) [pid = 1112] [serial = 301] [outer = 000001D939625400] 22:06:59 INFO - GECKO(1112) | ++DOCSHELL 000001D941C2D000 == 20 [pid = 1112] [id = {46d79c13-70fc-4c16-9802-f1e3ecb16857}] 22:06:59 INFO - GECKO(1112) | ++DOMWINDOW == 50 (000001D93A418000) [pid = 1112] [serial = 302] [outer = 0000000000000000] 22:06:59 INFO - GECKO(1112) | ++DOCSHELL 000001D941C2D800 == 21 [pid = 1112] [id = {db5ff910-a7d2-4e36-9021-5258c29fdb5f}] 22:06:59 INFO - GECKO(1112) | ++DOMWINDOW == 51 (000001D93A418800) [pid = 1112] [serial = 303] [outer = 0000000000000000] 22:06:59 INFO - GECKO(1112) | ++DOMWINDOW == 52 (000001D93A41A000) [pid = 1112] [serial = 304] [outer = 000001D93A418800] 22:06:59 INFO - GECKO(1112) | ++DOCSHELL 00000221B4D40000 == 2 [pid = 4632] [id = {1087f229-49ee-4505-8fde-3871a196b658}] 22:06:59 INFO - GECKO(1112) | ++DOMWINDOW == 6 (00000221BC506C00) [pid = 4632] [serial = 161] [outer = 0000000000000000] 22:06:59 INFO - GECKO(1112) | ++DOMWINDOW == 7 (00000221BC50CC00) [pid = 4632] [serial = 162] [outer = 00000221BC506C00] 22:06:59 INFO - GECKO(1112) | ++DOMWINDOW == 53 (000001D93DB05800) [pid = 1112] [serial = 305] [outer = 000001D93A418000] 22:06:59 INFO - GECKO(1112) | ++DOMWINDOW == 8 (00000221BC510000) [pid = 4632] [serial = 163] [outer = 00000221BC506C00] 22:06:59 INFO - GECKO(1112) | --DOCSHELL 000001DBA9E3D000 == 1 [pid = 7468] [id = {9b6a835d-c2e7-46ab-8af8-8962ee0d6260}] 22:06:59 INFO - TEST-INFO | started process screenshot 22:06:59 INFO - TEST-INFO | screenshot: exit 0 22:06:59 INFO - Buffered messages logged at 22:06:58 22:06:59 INFO - 728 INFO Entering test bound testDoesNotShowDoorhangerForBackgroundWindow 22:06:59 INFO - Buffered messages finished 22:06:59 ERROR - 729 INFO TEST-UNEXPECTED-FAIL | browser/components/customizableui/test/browser_panelUINotifications_multiWindow.js | The background window's doorhanger is closed. - Got showing, expected closed 22:06:59 INFO - Stack trace: 22:06:59 INFO - chrome://mochikit/content/browser-test.js:test_is:1271 22:06:59 INFO - chrome://mochitests/content/browser/browser/components/customizableui/test/browser_panelUINotifications_multiWindow.js:testDoesNotShowDoorhangerForBackgroundWindow/<:25 22:06:59 INFO - Not taking screenshot here: see the one that was previously logged 22:06:59 ERROR - 730 INFO TEST-UNEXPECTED-FAIL | browser/components/customizableui/test/browser_panelUINotifications_multiWindow.js | The background window has a badge. - Got false, expected true 22:06:59 INFO - Stack trace: 22:06:59 INFO - chrome://mochikit/content/browser-test.js:test_is:1271 22:06:59 INFO - chrome://mochitests/content/browser/browser/components/customizableui/test/browser_panelUINotifications_multiWindow.js:testDoesNotShowDoorhangerForBackgroundWindow/<:26 22:06:59 INFO - GECKO(1112) | --DOMWINDOW == 5 (000001DBB1B1A800) [pid = 7468] [serial = 33] [outer = 0000000000000000] [url = about:blank] 22:06:59 INFO - 731 INFO TEST-PASS | browser/components/customizableui/test/browser_panelUINotifications_multiWindow.js | update-manual doorhanger is showing. - this is the same failure on opt/debug and seems to be early in the test. [1] https://taskcluster-artifacts.net/LBKHOPooTnG9hujvz0tc9Q/0/public/logs/live_backing.log

As all the other browser-chrome tests work, I am inclined to skip this on windows-10 in the short term. Do you have concerns with that or suggestions of things to try?

Embarrassingly, this test has always failed for me locally on my win10 machine and I always just assumed it was something about my machine (maybe that it's hidpi), but given this maybe we can just actually fix the test (all the more because I can reproduce failures locally!).

Comment on attachment 8958805 [details] Bug 1445350 - fix browser_panelUINotifications_multiWindow.js so it doesn't fail on win10, https://reviewboard.mozilla.org/r/227714/#review233506

Autolanding this whenever autoland autolands it (I've clicked the button). :jmaher, can you check if this helps you? :-)

Pushed by gijskruitbosch@gmail.com: https://hg.mozilla.org/integration/autoland/rev/51b5d10855c9 fix browser_panelUINotifications_multiWindow.js so it doesn't fail on win10, r=dthayer

this appears to fix the problem, thanks!