#[markdown(off)]
Filed by: egao [at] mozilla.com

https://treeherder.mozilla.org/logviewer.html#?job_id=226341290&repo=try

https://queue.taskcluster.net/v1/task/I_BwI97fQ5qgmBZsLJxqjg/runs/0/artifacts/public/logs/live_backing.log

more context from the log file:
08:09:33 INFO - TEST-START | browser/components/sessionstore/test/browser_async_flushes.js
08:09:33 INFO - GECKO(10488) | Et tu, Brute?
08:09:33 INFO - GECKO(10488) | Exiting due to channel error.
08:09:33 INFO - GECKO(10488) | ###!!! [Parent][MessageChannel] Error: (msgtype=0x33000B,name=PCompositorWidget::Msg_UnobserveVsync) Channel error: cannot send/recv
08:09:33 INFO - GECKO(10488) | ###!!! [Parent][MessageChannel] Error: (msgtype=0x33000B,name=PCompositorWidget::Msg_UnobserveVsync) Channel error: cannot send/recv
08:09:33 INFO - GECKO(10488) | Exiting due to channel error.
08:09:33 INFO - GECKO(10488) | Exiting due to channel error.
08:09:33 INFO - GECKO(10488) | Exiting due to channel error.
08:09:33 INFO - GECKO(10488) | Exiting due to channel error.
08:09:33 INFO - TEST-INFO | Main app process: exit c0000409
08:09:33 INFO - Buffered messages logged at 08:09:32
08:09:33 INFO - Entering test bound test_flush
08:09:33 INFO - Buffered messages logged at 08:09:33
08:09:33 INFO - Console message: [JavaScript Error: "The character encoding of the HTML document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the page must be declared in the document or in the transfer protocol." {file: "http://example.com/browser/browser/components/sessionstore/test/file_async_flushes.html" line: 0}]
08:09:33 INFO - TEST-PASS | browser/components/sessionstore/test/browser_async_flushes.js | there is a single history entry -
08:09:33 INFO - TEST-PASS | browser/components/sessionstore/test/browser_async_flushes.js | there are two shistory entries -
08:09:33 INFO - Leaving test bound test_flush
08:09:33 INFO - Entering test bound test_crash
08:09:33 INFO - Console message: [JavaScript Error: "The character encoding of the HTML document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the page must be declared in the document or in the transfer protocol." {file: "http://example.com/browser/browser/components/sessionstore/test/file_async_flushes.html" line: 0}]
08:09:33 INFO - TEST-PASS | browser/components/sessionstore/test/browser_async_flushes.js | there is a single history entry -
08:09:33 INFO - Buffered messages finished
08:09:33 ERROR - TEST-UNEXPECTED-FAIL | browser/components/sessionstore/test/browser_async_flushes.js | application terminated with exit code 3221226505
08:09:33 INFO - runtests.py | Application ran for: 0:01:50.842000
08:09:33 INFO - zombiecheck | Reading PID log: c:\users\testdr~1\appdata\local\temp\tmp_9upstpidlog
08:09:33 INFO - ==> process 11900 launched child process 11936 ("C:\tasks\task_1549439521\build\application\firefox\firefox.exe" -contentproc --channel="11900.0.465678634\1187476568" -parentBuildID 20190205155112 -greomni "C:\tasks\task_1549439521\build\application\firefox\omni.ja" -appomni "C:\tasks\task_1549439521\build\application\firefox\browser\omni.ja" -appdir "C:\tasks\task_1549439521\build\application\firefox\browser" - 11900 "\.\pipe\gecko-crash-server-pipe.11900" 2584 gpu)
08:09:33 INFO - ==> process 11900 launched child process 10292 ("C:\tasks\task_1549439521\build\application\firefox\firefox.exe" -contentproc --channel="11900.6.30063177\373163159" -childID 1 -isForBrowser -prefsHandle 2200 -prefMapHandle 2020 -prefsLen 1 -prefMapSize 193625 -parentBuildID 20190205155112 -greomni "C:\tasks\task_1549439521\build\application\firefox\omni.ja" -appomni "C:\tasks\task_1549439521\build\application\firefox\browser\omni.ja" -appdir "C:\tasks\task_1549439521\build\application\firefox\browser" - 11900 "\.\pipe\gecko-crash-server-pipe.11900" 2608 tab)

Here is the last test-pass:
https://searchfox.org/mozilla-central/source/browser/components/sessionstore/test/browser_async_flushes.js#56

this test only runs if crashreporter is available.

Try run: https://treeherder.mozilla.org/#/jobs?repo=try&group_state=expanded&revision=33a2fa7bf0d27184a606318f80ec00d5ef2387d8&selectedJob=231977443

As of mozilla-central revision 78601ca this test is no longer failing.

In the try run above the test has been remapped to browser-chrome-5 chunk instead of 2.

23:46:06     INFO - TEST-START | browser/components/sessionstore/test/browser_async_flushes.js
23:46:06     INFO - GECKO(1924) | Et tu, Brute?
23:46:07     INFO - GECKO(1924) | ###!!! [Parent][MessageChannel] Error: (msgtype=0x1E009A,name=PBrowser::Msg_UpdateNativeWindowHandle) Channel error: cannot send/recv
23:46:07     INFO - GECKO(1924) | ###!!! [Parent][MessageChannel] Error: (msgtype=0x1E0089,name=PBrowser::Msg_Destroy) Channel error: cannot send/recv
23:46:07     INFO - GECKO(1924) | [Parent 10456, Gecko_IOThread] WARNING: file z:/build/build/src/ipc/chromium/src/base/process_util_win.cc, line 160
23:46:07     INFO - GECKO(1924) | about:tabcrashed loaded and ready
23:46:09     INFO - GECKO(1924) | No .extra file for dumpID: 7abf310a-695e-4427-bf07-e523ffcd2abd
23:46:09     INFO - GECKO(1924) | Crash cleaned up
23:46:10     INFO - GECKO(1924) | MEMORY STAT | vsize 6248MB | vsizeMaxContiguous 67227783MB | residentFast 521MB | heapAllocated 144MB
23:46:10     INFO - TEST-OK | browser/components/sessionstore/test/browser_async_flushes.js | took 3574ms

Closing this bug as resolved.