1713893 - browser_new_tab_in_privilegedabout_process_pref.js test skipped in 'browser/base/content/test/tabs/browser.ini' for Fission

Status: RESOLVED DUPLICATE of bug 1643998

(Firefox :: Tabbed Browser, task)

Description

[Andrew Halberstadt [:ahal]]

The following tests were disabled in browser/base/content/test/tabs/browser.ini due to new Fission platform triage:
browser_new_tab_in_privilegedabout_process_pref.js

Full diff:

--- a/browser/base/content/test/tabs/browser.ini
+++ b/browser/base/content/test/tabs/browser.ini
@@ -73,17 +73,20 @@ skip-if = os == 'mac' # Skipped because 
 [browser_navigate_home_focuses_addressbar.js]
 [browser_navigatePinnedTab.js]
 [browser_new_file_whitelisted_http_tab.js]
 skip-if = !e10s # Test only relevant for e10s.
 [browser_new_tab_insert_position.js]
 skip-if = (debug && os == 'linux' && bits == 32) #Bug 1455882, disabled on Linux32 for almost permafailing
 support-files = file_new_tab_page.html
 [browser_new_tab_in_privilegedabout_process_pref.js]
-skip-if = !e10s || (os == 'linux' && debug && bits == 64) # Pref and test only relevant for e10s, Bug 1581500.
+skip-if =
+    !e10s
+    os == 'linux' && debug && bits == 64  # Pref and test only relevant for e10s, Bug 1581500.
+    fission && os == "mac" && !debug  # New platform triage
 [browser_privilegedmozilla_process_pref.js]
 skip-if = !e10s # Pref and test only relevant for e10s.
 [browser_newwindow_tabstrip_overflow.js]
 [browser_open_newtab_start_observer_notification.js]
 [browser_opened_file_tab_navigated_to_web.js]
 [browser_overflowScroll.js]
 [browser_paste_event_at_middle_click_on_link.js]
 support-files = file_anchor_elements.html

See the following try push for failures:
https://treeherder.mozilla.org/jobs?repo=try&revision=ad7a18fdad3b8e35b44152c16d94babb80387cd8

To run these failures in your own try push, first revert the skip-if
annotations, then run:

$ ./mach try fuzzy --rebuild 3 browser/base/content/test/tabs/browser.ini

Then use the fuzzy interface to select the task(s) which are relevant to the
removed skip-if expression(s). Please note the failure may be intermittent
and/or been fixed since the triage took place.

Comment 1

[Chris Peterson [:cpeterson]]

We need to determine whether this browser-chrome test failure should block shipping Fission. Tracking for Fission Milestone M7a for the initial audit. Then we can decide whether to move this bug to Fission M8 or post-MVP (Fission Future).

Here is a recent Try run for Fission browser-chrome:

https://treeherder.mozilla.org/jobs?repo=try&revision=ad7a18fdad3b8e35b44152c16d94babb80387cd8

Comment 2

[Nika Layzell [:nika] (ni? for response)]

The description of this bug notes that this test was only marked as skipped for !debug, but it appears that there is also a macOS debug failure of this test (https://treeherder.mozilla.org/logviewer?job_id=341440984&repo=try&lineNumber=22994). It's quite surprising and unfortunate that this test would be failing at all, and it suggests some sort of race is happening. This seems to be backed up by warnings being emitted after the test fails complaining that a process switch was unable to complete:

[task 2021-06-01T18:50:39.236Z] 18:50:39     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/tabs/browser_new_tab_in_privilegedabout_process_pref.js | Check that about:newtab is in privileged about: content process after location change. - Got 2141, expected 1886
[task 2021-06-01T18:50:39.236Z] 18:50:39     INFO - Stack trace:
[task 2021-06-01T18:50:39.236Z] 18:50:39     INFO - chrome://mochikit/content/browser-test.js:test_is:1362
[task 2021-06-01T18:50:39.236Z] 18:50:39     INFO - chrome://mochitests/content/browser/browser/base/content/test/tabs/browser_new_tab_in_privilegedabout_process_pref.js:process_switching_through_navigation_features/<:214
[task 2021-06-01T18:50:39.236Z] 18:50:39     INFO - Leaving test bound process_switching_through_navigation_features
[task 2021-06-01T18:50:39.237Z] 18:50:39     INFO - GECKO(1883) | [Parent 1883, Main Thread] WARNING: WebProgress Ignored: no longer current window global: file /builds/worker/checkouts/gecko/dom/ipc/BrowserParent.cpp:2938
[task 2021-06-01T18:50:39.237Z] 18:50:39     INFO - GECKO(1883) | [Parent 1883, Main Thread] WARNING: WebProgress Ignored: no longer current window global: file /builds/worker/checkouts/gecko/dom/ipc/BrowserParent.cpp:2938
[task 2021-06-01T18:50:39.238Z] 18:50:39     INFO - GECKO(1883) | [Child 1886, Main Thread] WARNING: NS_ENSURE_TRUE(!mHasOrHasHadOwnerWindow || mOwnerWindow) failed: file /builds/worker/checkouts/gecko/dom/events/DOMEventTargetHelper.cpp:327
[task 2021-06-01T18:50:39.239Z] 18:50:39     INFO - GECKO(1883) | [Parent 1883, Main Thread] WARNING: Error finishing PendingRemotenessChange!: file /builds/worker/checkouts/gecko/docshell/base/CanonicalBrowsingContext.cpp:1277
[task 2021-06-01T18:50:39.239Z] 18:50:39     INFO - GECKO(1883) | [Parent 1883, Main Thread] WARNING: 'aOwner->IsDiscarded()', file /builds/worker/workspace/obj-build/dist/include/mozilla/dom/SyncedContextInlines.h:92

My main guess right now is that the failure is somehow related to the fact that promiseLocaiton (https://searchfox.org/mozilla-central/rev/74f3c420ee54001059e1850bef3be876749ff873/browser/base/content/test/tabs/browser_new_tab_in_privilegedabout_process_pref.js#193-196) was used to wait for the previous load to finish, rather than browserLoaded, and perhaps the final load event for the previous test's ABOUT_NEWTAB is being detected in the browserLoaded call due to the page not being pulled from bfcache instead of the one we're actually interested in.

Someone who has a macOS machine should attempt to reproduce this failure locally with DocumentChannel:5 logging for help figuring out what is going wrong here.

Comment 3

[Neha Kochar [:neha]]

Markus tried to reproduce locally but couldn't. Said that this does not seem to be related to anything Mac-specific. Maybe Anny can try this after bug 1713894.

Comment 4

[Anny Gakhokidze [:annyG]]

fixed by kris!