+++ This bug was initially created as a clone of Bug #1048080 +++ https://tbpl.mozilla.org/php/getParsedLog.php?id=45224618&tree=B2g-Inbound 23:18:56 INFO - 08-05 06:17:03.598 I/GeckoDump( 757): ⰲ겿{"action":"log","time":1407219423598,"thread":"","pid":null,"source":"mochitest","level":"INFO","message":"MEMORY STAT residentFast after test: 39485440"}ⰲ겿 23:18:56 INFO - 08-05 06:17:03.608 I/GeckoDump( 757): ⰲ겿{"action":"log","time":1407219423615,"thread":"","pid":null,"source":"mochitest","level":"INFO","message":"MEMORY STAT heapAllocated after test: 18831488"}ⰲ겿 23:18:56 INFO - 08-05 06:17:03.728 I/Gecko ( 875): 23:18:56 INFO - 08-05 06:17:03.728 I/Gecko ( 875): ###!!! [Child][MessageChannel] Error: Channel closing: too late to send/recv, messages will be lost 23:18:56 INFO - 08-05 06:17:03.728 I/Gecko ( 875): 23:18:56 INFO - 08-05 06:17:04.049 I/GeckoDump( 757): ⰲ겿{"action":"test_end","time":1407219424051,"thread":"","pid":null,"source":"mochitest","test":"/tests/dom/ipc/tests/test_NuwaProcessDeadlock.html","status":"OK","message":"Finished in 26589ms","extra":{"runtime":26589}}ⰲ겿 23:18:56 INFO - 08-05 06:17:04.668 E/GeckoConsole( 757): [JavaScript Warning: "The character encoding of a framed document was not declared. The document may appear different if viewed without the document framing it." {file: "http://mochi.test:8888/tests/SimpleTest/iframe-between-tests.html" line: 0}] 23:18:56 INFO - 08-05 06:17:04.929 I/GeckoDump( 757): ⰲ겿{"action":"test_start","time":1407219424918,"thread":"","pid":null,"source":"mochitest","test":"/tests/dom/ipc/tests/test_child_docshell.html"}ⰲ겿 23:18:56 INFO - 08-05 06:17:06.688 I/ServiceManager( 33): service 'media.resource_manager' died 23:18:56 INFO - 08-05 06:17:06.688 I/ServiceManager( 33): service 'permission' died 23:18:56 INFO - Return code: 0 23:18:56 INFO - Running command: ['ps', '-C', 'emulator'] 23:18:56 INFO - Copy/paste: ps -C emulator 23:18:56 INFO - PID TTY TIME CMD 23:18:56 ERROR - Return code: 1 23:18:56 INFO - Running command: ['/builds/slave/test/build/emulator/b2g-distro/out/host/linux-x86/bin/adb', 'devices'] 23:18:56 INFO - Copy/paste: /builds/slave/test/build/emulator/b2g-distro/out/host/linux-x86/bin/adb devices 23:18:56 INFO - List of devices attached 23:18:56 INFO - Return code: 0 23:18:56 INFO - Copying /builds/slave/test/build/emulator-5554.log to /builds/slave/test/build/blobber_upload_dir/emulator-5554.log 23:18:56 INFO - Copying /builds/slave/test/build/qemu.log to /builds/slave/test/build/blobber_upload_dir/qemu.log 23:18:56 INFO - TinderboxPrint: mochitest<br/><em class="testfail">T-FAIL</em> 23:18:56 WARNING - # TBPL WARNING #

So it's running the command ['ps', '-C', 'emulator'] that returns 1? (meaning the emulator is killed before we reach that point)

What do you think we could do about this?

The ps -C emulator call was added in attempt to figure out whether timeouts we were seeing were caused by the emulator crashing or not. Unfortunately it is broken because by the time we run that command, the automation has cleaned up the emulator one way or another. It is buying us nothing, so we can safely remove it. However it only gets run if mozharness detects something else wrong (a failure, crash or timeout): https://hg.mozilla.org/build/mozharness/file/1cbea7b85889/scripts/b2g_emulator_unittest.py#l406 So the real bug here is that something is going wrong and isn't showing up in the tbpl summary (though mozharness is still detecting it).

Actually, without that return code 1, jobs like this wouldn't even turn orange. So at least it's doing that..

In those logs the tests aren't even being started. The last thing dumped to stdout is: 07:11:47 INFO - 08-12 14:10:39.002 I/Gecko ( 736): ###!!! [Child][MessageChannel::SendAndWait] Error: Channel error: cannot send/recv 07:11:47 INFO - 08-12 14:10:39.002 I/Gecko ( 736): 07:11:47 INFO - 08-12 14:10:39.002 I/Gecko ( 736): [Child 736] WARNING: content process _exit()ing: file ../../../gecko/dom/ipc/ContentChild.cpp, line 1486