Investigate flaky sequential/test-net-connect-local-error on FreeBSD

Version: v8.0.0-pre
Platform: freebsd
Subsystem: test

https://ci.nodejs.org/job/node-test-commit-freebsd/9081/nodes=freebsd10-64/consoleFull

not ok 1453 sequential/test-net-connect-local-error
  ---
  duration_ms: 0.294
  severity: fail
  stack: |-
    assert.js:92
      throw new AssertionError({
      ^
    
    AssertionError [ERR_ASSERTION]: 'EADDRINUSE' === 'ECONNREFUSED'
        at Socket.onError (/usr/home/iojs/build/workspace/node-test-commit-freebsd/nodes/freebsd10-64/test/sequential/test-net-connect-local-error.js:14:10)
        at Socket.<anonymous> (/usr/home/iojs/build/workspace/node-test-commit-freebsd/nodes/freebsd10-64/test/common/index.js:504:15)
        at emitOne (events.js:115:13)
        at Socket.emit (events.js:210:7)
        at emitErrorNT (net.js:1337:8)
        at _combinedTickCallback (internal/process/next_tick.js:102:11)
        at process._tickCallback (internal/process/next_tick.js:161:9)

The test was recently updated to check for ECONNREFUSED. However, we are seeing EADDRINUSE sometimes on FreeBSD in CI as seen above.

Possible bug in the FreeBSD operating system or quirk (relative to our other hosts) in the way it handles open/half-open/whatever ports? (I normally wouldn't jump to Blame-The-Operating-System as the likely cause right off the bat, but this is looking very familiar to me and I seem to recall it, but I can't find anything so maybe I'm imagining it?)

/cc @sebastianplesciuc @refack @nodejs/testing