https://treeherder.mozilla.org/logviewer.html#?job_id=213332123&repo=try&lineNumber=3087 [task 2018-11-22T05:56:27.410Z] 05:56:27 INFO - TEST-OK | /fetch/corb/style-html-correctly-labeled.sub.html | took 204ms [task 2018-11-22T05:56:28.193Z] 05:56:28 ERROR - adb get_process_list: [task 2018-11-22T05:56:28.534Z] 05:56:28 INFO - Browser exited with return code 0

There are several issues to look into here: I think this hits wpt (I haven't seen any such failures in other test suites) because the wpt "Fennec browser" polls the returncode property, which in turn calls process_exist/get_process_list. The error handling is suspect: Odd that no ADBError/ADBTimeoutError is reported. We could possibly surface such an error to trigger retry. (Or expand the retry list to include "adb get_process_list"?) And why/how is get_process_list failing in the first place?

(In reply to Geoff Brown [:gbrown] from comment #1) > The error handling is suspect: Odd that no ADBError/ADBTimeoutError is > reported. We could possibly surface such an error to trigger retry. (Or > expand the retry list to include "adb get_process_list"?) Now addressed by bug 1509614. > And why/how is get_process_list failing in the first place? It is a known problem observed for some time in bug 1466657.

I hope that bug 1512686 will reduce the complexity of each check for process existence -- less adb traffic and parsing, fewer process table lookups, less opportunity for failure.

It seems like these errors happen more frequently when we poll frequently for process existence. 0.1 seconds seems too short to me - I'll feel better if we increase it like this, to 0.5 seconds. https://treeherder.mozilla.org/#/jobs?repo=try&tier=1%2C2%2C3&revision=20c4becb37e5999405bb11fcd885c8008cbaa122

Comment on attachment 9030048 [details] [diff] [review] increase poll interval - poll less often Worth a shot, at least.

Pushed by gbrown@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/cc5f0fb59ada Poll remote process less often during startup and shutdown; r=kwierso