Filed by: egao [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer.html#?job_id=278675863&repo=try
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/Awl10Wl9Sr2Hifhsy5jytw/runs/0/artifacts/public/logs/live_backing.log

suite: mochitest-a11y

context:

multiple failures all in the same file - likely different test cases.

task 2019-11-28T21:11:39.101Z] 21:11:39 INFO - TEST-UNEXPECTED-FAIL | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAfterOffset (line start): wrong text (got 'longfr', expected: 'longf'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.101Z] 21:11:39 INFO - SimpleTest.ok@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:277:18
[task 2019-11-28T21:11:39.101Z] 21:11:39 INFO - testTextHelper@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:747:12
[task 2019-11-28T21:11:39.101Z] 21:11:39 INFO - testTextSuperHelper@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:696:19
[task 2019-11-28T21:11:39.101Z] 21:11:39 INFO - testTextAfterOffset@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:199:22
[task 2019-11-28T21:11:39.101Z] 21:11:39 INFO - genericMoveTo_finalCheck@chrome://mochitests/content/a11y/accessible/tests/mochitest/text/test_atcaretoffset.html:345:15
[task 2019-11-28T21:11:39.101Z] 21:11:39 INFO - eventQueue_processNextInvoker@chrome://mochitests/content/a11y/accessible/tests/mochitest/events.js:343:17
[task 2019-11-28T21:11:39.101Z] 21:11:39 INFO - eventQueue_processNextInvokerInTimeout/<@chrome://mochitests/content/a11y/accessible/tests/mochitest/events.js:505:15
[task 2019-11-28T21:11:39.102Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAfterOffset (line start): wrong start offset(got '12', expected: '12'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.102Z] 21:11:39 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-11-28T21:11:39.104Z] 21:11:39 INFO - TEST-UNEXPECTED-FAIL | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAfterOffset (line start): wrong end offset(got '18', expected: '17'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.104Z] 21:11:39 INFO - SimpleTest.ok@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:277:18
[task 2019-11-28T21:11:39.104Z] 21:11:39 INFO - testTextHelper@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:773:12
[task 2019-11-28T21:11:39.104Z] 21:11:39 INFO - testTextSuperHelper@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:696:19
[task 2019-11-28T21:11:39.104Z] 21:11:39 INFO - testTextAfterOffset@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:199:22
[task 2019-11-28T21:11:39.104Z] 21:11:39 INFO - genericMoveTo_finalCheck@chrome://mochitests/content/a11y/accessible/tests/mochitest/text/test_atcaretoffset.html:345:15
[task 2019-11-28T21:11:39.104Z] 21:11:39 INFO - eventQueue_processNextInvoker@chrome://mochitests/content/a11y/accessible/tests/mochitest/events.js:343:17
[task 2019-11-28T21:11:39.104Z] 21:11:39 INFO - eventQueue_processNextInvokerInTimeout/<@chrome://mochitests/content/a11y/accessible/tests/mochitest/events.js:505:15
[task 2019-11-28T21:11:39.104Z] 21:11:39 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-11-28T21:11:39.108Z] 21:11:39 INFO - TEST-UNEXPECTED-FAIL | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAfterOffset (line end): wrong text (got 'longfr', expected: 'longf'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.108Z] 21:11:39 INFO - SimpleTest.ok@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:277:18
[task 2019-11-28T21:11:39.108Z] 21:11:39 INFO - testTextHelper@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:747:12
[task 2019-11-28T21:11:39.108Z] 21:11:39 INFO - testTextSuperHelper@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:696:19
[task 2019-11-28T21:11:39.108Z] 21:11:39 INFO - testTextAfterOffset@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:199:22
[task 2019-11-28T21:11:39.108Z] 21:11:39 INFO - genericMoveTo_finalCheck@chrome://mochitests/content/a11y/accessible/tests/mochitest/text/test_atcaretoffset.html:345:15
[task 2019-11-28T21:11:39.108Z] 21:11:39 INFO - eventQueue_processNextInvoker@chrome://mochitests/content/a11y/accessible/tests/mochitest/events.js:343:17
[task 2019-11-28T21:11:39.108Z] 21:11:39 INFO - eventQueue_processNextInvokerInTimeout/<@chrome://mochitests/content/a11y/accessible/tests/mochitest/events.js:505:15
[task 2019-11-28T21:11:39.108Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAfterOffset (line end): wrong start offset(got '12', expected: '12'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.108Z] 21:11:39 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-11-28T21:11:39.108Z] 21:11:39 INFO - TEST-UNEXPECTED-FAIL | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAfterOffset (line end): wrong end offset(got '18', expected: '17'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.109Z] 21:11:39 INFO - SimpleTest.ok@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:277:18
[task 2019-11-28T21:11:39.109Z] 21:11:39 INFO - testTextHelper@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:773:12
[task 2019-11-28T21:11:39.109Z] 21:11:39 INFO - testTextSuperHelper@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:696:19
[task 2019-11-28T21:11:39.109Z] 21:11:39 INFO - testTextAfterOffset@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:199:22
[task 2019-11-28T21:11:39.109Z] 21:11:39 INFO - genericMoveTo_finalCheck@chrome://mochitests/content/a11y/accessible/tests/mochitest/text/test_atcaretoffset.html:345:15
[task 2019-11-28T21:11:39.109Z] 21:11:39 INFO - eventQueue_processNextInvoker@chrome://mochitests/content/a11y/accessible/tests/mochitest/events.js:343:17
[task 2019-11-28T21:11:39.109Z] 21:11:39 INFO - eventQueue_processNextInvokerInTimeout/<@chrome://mochitests/content/a11y/accessible/tests/mochitest/events.js:505:15
[task 2019-11-28T21:11:39.109Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextBeforeOffset (word start): wrong text (got 'hello ', expected: 'hello '), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.109Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextBeforeOffset (word start): wrong start offset(got '3', expected: '3'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.109Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextBeforeOffset (word start): wrong end offset(got '9', expected: '9'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.111Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextBeforeOffset (word end): wrong text (got ' hello', expected: ' hello'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.111Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextBeforeOffset (word end): wrong start offset(got '2', expected: '2'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.111Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextBeforeOffset (word end): wrong end offset(got '8', expected: '8'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.111Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAtOffset (word start): wrong text (got 'my ', expected: 'my '), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.112Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAtOffset (word start): wrong start offset(got '9', expected: '9'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.112Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAtOffset (word start): wrong end offset(got '12', expected: '12'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.112Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAtOffset (word end): wrong text (got ' my', expected: ' my'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.114Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAtOffset (word end): wrong start offset(got '8', expected: '8'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.114Z] 21:11:39 INFO - TEST-PASS | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAtOffset (word end): wrong end offset(got '11', expected: '11'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.114Z] 21:11:39 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-11-28T21:11:39.115Z] 21:11:39 INFO - TEST-UNEXPECTED-FAIL | accessible/tests/mochitest/text/test_atcaretoffset.html | getTextAfterOffset (word start): wrong text (got 'longfr', expected: 'longf'), offset: -2, id: 'ta_wrapped' ;
[task 2019-11-28T21:11:39.115Z] 21:11:39 INFO - SimpleTest.ok@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:277:18
[task 2019-11-28T21:11:39.115Z] 21:11:39 INFO - testTextHelper@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:747:12
[task 2019-11-28T21:11:39.115Z] 21:11:39 INFO - testTextSuperHelper@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:696:19
[task 2019-11-28T21:11:39.115Z] 21:11:39 INFO - testTextAfterOffset@chrome://mochitests/content/a11y/accessible/tests/mochitest/text.js:199:22
[task 2019-11-28T21:11:39.115Z] 21:11:39 INFO - genericMoveTo_finalCheck@chrome://mochitests/content/a11y/accessible/tests/mochitest/text/test_atcaretoffset.html:345:15
[task 2019-11-28T21:11:39.115Z] 21:11:39 INFO - eventQueue_processNextInvoker@chrome://mochitests/content/a11y/accessible/tests/mochitest/events.js:343:17
[task 2019-11-28T21:11:39.115Z] 21:11:39 INFO - eventQueue_processNextInvokerInTimeout/<@chrome://mochitests/content/a11y/accessible/tests/mochitest/events.js:505:15

:Jamie - I am not sure who to ping for this test failure that I am observing. Some details:

In the mochitest-a11y chunk this particular test produces a long list of failures, when run on ubuntu1804 which is a new docker test image that I am working to replace ubuntu1604 with.

Ubuntu1804 runs with GNOME3 window manager which have already caused some issues for other tests, and I wonder if that is a similar story here.

Confirmed locally. This occurs because for some reason, specifying cols="5" (which is supposed to limit each line to 5 characters) ends up limiting to 6 characters on these systems:

data:text/html,<textarea id="ta_wrapped" cols="5">hi hello my longfriend t sq t</textarea>

Observe that there is a line "longfr", which is 6 characters long. It should be "longf".

MDN notes that cols is specified in "average character widths". Because we're dealing with average here, I guess that could result in some edge cases. However, this seems to fail all the time for me:

data:text/html,<textarea cols="5">testing testing</textarea>

Observe "testin" instead of "testi".

Emilio, you're probably not the right person to ping about this, but would you have any idea who is?

This is actually an extremely long-standing bug (bug 33654), which is that we add the width of the scrollbars to the textarea even though in some cases like this would be unnecessary.

Probably the scrollbar width is different than on the current automation which allows for the extra character.

You can fix this by setting, e.g., scrollbar-width: none on the <textarea>, with a reference to that bug, probably.

Previously, due to bug 33654, we incorrectly added the width of the scrollbars to the textarea.
This was causing lines to be limited to 6 characters on ubuntu 18.04, even though we set cols="5" and thus expect 5 characters.
Setting scrollbar-width: none on the textarea works around this.

Thanks much, Emilio.

:egao, are you able to try the patch from comment 4? I couldn't find test-linux64 using mach try chooser locally.

:jamie - I have pushed a new try run for all test-linux64 mochitest-a11y, using the ubuntu1804 image: https://treeherder.mozilla.org/#/jobs?repo=try&revision=986f6907e66ac32e41ee6aa9ec79025538888925

(In reply to Edwin Takahashi (:egao, :etakahashi) from comment #6)

:jamie - I have pushed a new try run for all test-linux64 mochitest-a11y, using the ubuntu1804 image: https://treeherder.mozilla.org/#/jobs?repo=try&revision=986f6907e66ac32e41ee6aa9ec79025538888925

Was this based on my patch in comment 4 or latest central? This hasn't been landed in central yet. I'd prefer not to land this before knowing whether it definitely fixes the issue. I'm just not sure how to trigger a try run for this patch using the Ubuntu 18.04 image.

:jamie - the ubuntu1804 image is available to use on try and already have landed on mozilla-central. To push to try against the ubuntu1804 image, please attach the flag ./mach try fuzzy --ubuntu-bionic.

https://treeherder.mozilla.org/#/jobs?repo=try&revision=ecf0da25232cc2da23fea064ef4a77a239c8630e

https://hg.mozilla.org/mozilla-central/rev/d60b79548cb5