investigate flaky test-cluster-concurrent-disconnect

[Trott]

• Test: parallel/test-cluster-concurrent-disconnect
• Platform: osx11-arm
• Console Output:

  ...
not ok 243 parallel/test-cluster-concurrent-disconnect
  ---
  duration_ms: 0.106
  severity: fail
  exitcode: 1
  stack: |-
    node:assert:123
      throw new AssertionError(obj);
      ^
    
    AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:
    + actual - expected
    
    + 'ENOTCONN'
    - 'EPIPE'
        at Worker.<anonymous> (/Users/iojs/build/workspace/node-test-commit-osx-arm/nodes/osx11/test/parallel/test-cluster-concurrent-disconnect.js:29:14)
        at Worker.emit (node:events:365:28)
        at ChildProcess.<anonymous> (node:internal/cluster/worker:30:12)
        at ChildProcess.emit (node:events:365:28)
        at node:internal/child_process:853:39
        at processTicksAndRejections (node:internal/process/task_queues:78:11) {
      generatedMessage: true,
      code: 'ERR_ASSERTION',
      actual: 'ENOTCONN',
      expected: 'EPIPE',
      operator: 'strictEqual'
    }
    node:events:342
          throw er; // Unhandled 'error' event
          ^
    
    Error: write EPIPE
        at process.target._send (node:internal/child_process:849:20)
        at process.target.send (node:internal/child_process:722:19)
        at sendHelper (node:internal/cluster/utils:27:15)
        at send (node:internal/cluster/child:216:10)
        at checkWaitingCount (node:internal/cluster/child:234:9)
        at Worker._disconnect (node:internal/cluster/child:249:3)
        at Worker.disconnect (node:internal/cluster/child:256:5)
        at process.<anonymous> (/Users/iojs/build/workspace/node-test-commit-osx-arm/nodes/osx11/test/parallel/test-cluster-concurrent-disconnect.js:46:26)
        at process.emit (node:events:377:35)
        at emit (node:internal/child_process:920:12)
    Emitted 'error' event on Worker instance at:
        at process.<anonymous> (node:internal/cluster/worker:30:12)
        at process.emit (node:events:365:28)
        at node:internal/child_process:853:39
        at processTicksAndRejections (node:internal/process/task_queues:78:11) {
      errno: -32,
      code: 'EPIPE',
      syscall: 'write'
    }
    node:events:342
          throw er; // Unhandled 'error' event
          ^
    
    Error: write EPIPE
        at process.target._send (node:internal/child_process:849:20)
        at process.target.send (node:internal/child_process:722:19)
        at sendHelper (node:internal/cluster/utils:27:15)
        at send (node:internal/cluster/child:216:10)
        at checkWaitingCount (node:internal/cluster/child:234:9)
        at Worker._disconnect (node:internal/cluster/child:249:3)
        at Worker.disconnect (node:internal/cluster/child:256:5)
        at process.<anonymous> (/Users/iojs/build/workspace/node-test-commit-osx-arm/nodes/osx11/test/parallel/test-cluster-concurrent-disconnect.js:46:26)
        at process.emit (node:events:377:35)
        at emit (node:internal/child_process:920:12)
    Emitted 'error' event on Worker instance at:
        at process.<anonymous> (node:internal/cluster/worker:30:12)
        at process.emit (node:events:365:28)
        at node:internal/child_process:853:39
        at processTicksAndRejections (node:internal/process/task_queues:78:11) {
      errno: -32,
      code: 'EPIPE',
      syscall: 'write'
    }
    node:events:342
          throw er; // Unhandled 'error' event
          ^
    
    Error: write EPIPE
        at process.target._send (node:internal/child_process:849:20)
        at process.target.send (node:internal/child_process:722:19)
        at sendHelper (node:internal/cluster/utils:27:15)
        at send (node:internal/cluster/child:216:10)
        at checkWaitingCount (node:internal/cluster/child:234:9)
        at Worker._disconnect (node:internal/cluster/child:249:3)
        at Worker.disconnect (node:internal/cluster/child:256:5)
        at process.<anonymous> (/Users/iojs/build/workspace/node-test-commit-osx-arm/nodes/osx11/test/parallel/test-cluster-concurrent-disconnect.js:46:26)
        at process.emit (node:events:377:35)
        at emit (node:internal/child_process:920:12)
    Emitted 'error' event on Worker instance at:
        at process.<anonymous> (node:internal/cluster/worker:30:12)
        at process.emit (node:events:365:28)
        at node:internal/child_process:853:39
        at processTicksAndRejections (node:internal/process/task_queues:78:11) {
      errno: -32,
      code: 'EPIPE',
      syscall: 'write'
    }
  ...

• Build Links: https://ci.nodejs.org/job/node-test-commit-osx-arm/1036/nodes=osx11/consoleText