Noticed in bug 1233554 and bug 1235892. > There is also a screenshot of a dialog saying "The application classic guest > session has closed unexpectedly" [5] This is "indicator-session-service" crashing, I don't know if it's related or not. It would be interesting to know if this happens on other test runs. https://public-artifacts.taskcluster.net/PyrzBbC3TUiKYqUw9lIXQA/0/public/test_info//mozilla-test-fail-screenshot_w7dcIz.png https://public-artifacts.taskcluster.net/S-ivyrIiRJacSQ7TTT3Oyg/0/public/test_info//mozilla-test-fail-screenshot_V4rFhH.png https://public-artifacts.taskcluster.net/aut1NASmRqO-NIouXc09CA/0/public/test_info//mozilla-test-fail-screenshot_gFc41U.png

Dustin recommended to try disabling the guest account: http://www.howtogeek.com/117994/how-to-disable-ubuntus-guest-session-account

Unrelated (but maybe), we can see some crashes happen because dbus not being in place: http://people.mozilla.org/~armenzg/sattap/694578cb.png Nothing important said in here: https://bugs.launchpad.net/ubuntu/+source/software-center/+bug/975281 > software-center crashed with DBusException in __new__(): org.freedesktop.DBus.Error.FileNotFound: Failed to connect to socket /var/run/dbus/system_bus_socket: No such file or directory

My previous attempt was not sufficient. I will disable apport and see if we do better: http://howtoubuntu.org/how-to-disable-stop-uninstall-apport-error-reporting-in-ubuntu

For instane, in this push you can see mochitests failing like this: https://treeherder.mozilla.org/#/jobs?repo=try&revision=c63b24f60dd5&filter-searchStr=mochitest You can see the crash reporter stealing focus (which causes the time outs): https://public-artifacts.taskcluster.net/JdsIUOjTT--nlk1ON-uzCw/0/public/test_info//mozilla-test-fail-screenshot_AP2qPh.png 36 INFO TEST-UNEXPECTED-FAIL | dom/tests/mochitest/general/test_bug1170911.html | Test timed out. 37 INFO TEST-UNEXPECTED-FAIL | dom/tests/mochitest/general/test_bug1170911.html | [SimpleTest.finish()] waitForFocus() was called a different number of times from the number of callbacks run. Maybe the test terminated prematurely -- be sure to use SimpleTest.waitForExplicitFinish(). - got 1, expected +0 40 INFO TEST-UNEXPECTED-FAIL | dom/tests/mochitest/general/test_bug1170911.html | [SimpleTest.finish()] waitForFocus() was called a different number of times from the number of callbacks run. Maybe the test terminated prematurely -- be sure to use SimpleTest.waitForExplicitFinish(). - Result logged after SimpleTest.finish() 65 INFO TEST-UNEXPECTED-FAIL | dom/tests/mochitest/general/test_clipboard_events.html | Test timed out.

I pushed this image (straight off your try branch) as taskcluster/desktop-test:0.5.5. We can just skip 0.5.4 :)

https://hg.mozilla.org/integration/mozilla-inbound/rev/ad797c9b01aa8a8e38c9ee7b0f7979db2db4ac48 Bug 1238739 - Disable Ubuntu's app crash reporter (apport). Desktop-test 0.5.5. r=dustin