1093296 - B2G mochitests/mozrunner child process crash detection no longer working

Status: RESOLVED WONTFIX

(Testing :: Mochitest, defect)

Description

[Andrew Halberstadt [:ahal]]

See discussion starting at https://bugzilla.mozilla.org/show_bug.cgi?id=965705#c351

It seems like child process crashes are no longer being handled properly in b2g emulator mochitests (and possibly other suites too).

To reproduce, run mochitests on an emulator (which I'm currently having other troubles with.. sigh), and do "adb shell kill -6 <content pid>".

Expected:
Test run aborts immediately and crash stack dumped to stdout

Actual:
Test run times out until killAndGetStack is triggered

Comment 1

[Hsin-Yi Tsai (she/her) [:hsinyi]]

Hi John,
This blocks bug 965705 which happens frequently. Could you help dig this based on comment 0 first? Thank you.

Comment 2

[Hsin-Yi Tsai (she/her) [:hsinyi]]

I can easily reproduce the issue based on STR in comment 0.

Comment 3

[John Dai[:jdai]]

Sure, I'll take it.

Comment 4

[John Dai[:jdai]]

Attachment: Add mochitests/mozrunner child process crash detection.

When child process crashes, it sends "ipc:content-shutdown" message. Therefore, we should listen this message aborts test immediately.

Comment 5

[John Dai[:jdai]]

Hi Andrew,

May I have your feedback about this patch? 

Thanks.

Comment 6

[Andrew Halberstadt [:ahal]]

Hmm, I'm not sure if specialpowers is the best place to fix this. Not all flavours of mochitest use specialpowers, and I think this issue might affect test harnesses other than mochitest as well. It would be nice to have a more generic solution.

There's code in shell.js [1] that is supposed to call nsIAppStartup.quit() if the MOZ_CRASHREPORTER_SHUTDOWN environment variable is set. Mozrunner sets that variable [2], but for some reason the if statement in [1] doesn't seem to be getting hit. It would nice to put a breakpoint at that location to see what is going on, though I don't remember how to do that with emulators.

[1] https://dxr.mozilla.org/mozilla-central/source/b2g/chrome/content/shell.js#137
[2] https://dxr.mozilla.org/mozilla-central/source/testing/mozbase/mozrunner/mozrunner/base/device.py#26

Comment 7

[John Dai[:jdai]]

No longer work on it.

Comment 8

[Andrew Halberstadt [:ahal]]

The b2g mochitest code has been removed from mozilla-central, so let's WONTFIX.