Unit Test Stalling after merging 97515d9

Currently, all CI tests are stalled. They are in yellow. I found that it is stalled after

```
>>>> node/parallel
PASS : test-assert.js
PASS : test-http-status-message.js
PASS : test-http-write-head.js
PASS : test-net-bind-twice.js
PASS : test-net-end-without-connect.js
```

It seems related to latest merged PR 97515d9.
When I revert it, unit tests finish well on my local machine.