Investigate flaky test-vm-sigint

[Trott]

From time to time, test-vm-sigint.js fails on CI with no indication of what went wrong.

https://ci.nodejs.org/job/node-test-commit-linux/4202/nodes=centos5-32/console:

not ok 1066 parallel/test-vm-sigint
  ---
  duration_ms: 0.348

It's not timing out, but there's no assertion error either. It's just exiting with a bad code, I think?

/cc @addaleax

[addaleax]

fwiw, after you pinged me the first time on it, I ran the test with --repeat=100000 and it came back clean for me… any tips on how to get closer to the CI environment?

[addaleax]

Also… would segfaults or similar conditions present that way in the CI output?

[Trott]

Alas, not sure how to repeat it. I think segfaults would show up in the CI output, but... uh... /cc @nodejs/build on both questions, I guess. @nodejs/testing too?

[Trott]

Another today, this time on 64-bit CentOS 5.

https://ci.nodejs.org/job/node-test-commit-linux/4390/nodes=centos5-64/console:

not ok 1071 parallel/test-vm-sigint
  ---
  duration_ms: 0.161

[Trott]

Now that there's code added to print the signal, it fails like this:

not ok 1072 parallel/test-vm-sigint
# CRASHED (Signal: 12)

https://ci.nodejs.org/job/node-test-commit-linux/4427/nodes=centos5-64/console

/cc @santigimeno