taskcluster-worker 0.1.12 hang after task - script-engine

[jonasfj]

@bclary reports that worker crashes after running tasks. Not everytime, but often.

Logs:

1. https://gist.github.com/jonasfj/02cba8a930bcbe36f995529fa611d32e
2. https://gist.github.com/jonasfj/71356ee3a706ae6f72914ab0e532a8b5

(credits @bclary)

[bclary]

watchdog-stackdump-0.1.13.txt
https://gist.github.com/bclary/f8cf2f2414cfabcf3a7aa7e4c7dfb930

[jonasfj]

@bclary, are you looking at these task in the task inspector while they run... From stack trace I could suspect it's related to livelogs...

Maybe we should try to disable livelogs... I don't think we have static logs to replace them, but I can add a plugin for that...

[bclary]

I was definitely looking at the live logs on some of the tasks but I'm not sure I was looking at them for that particular task. I have set up the configuration to shutdown the worker on task completion so if I had looked at earlier tasks it shouldn't have affected this one. The next time I have a test run I will refrain from viewing the logs and see if it reproduces. I would hate to lose the ability to check on a running task.

[jonasfj]

Oh, if it is a livelog bug I want to know so we can fix it. We're not aiming to work around any of this..
Just identify what is wrong, so we can fix it :)

I started writing integration tests for script-engine, as we didn't have any... but I haven't run into this issue yet.