Unable to catch a intermittent and fatal "Error: not opened"

I am intermittently experiencing the Error: not opened and ECONNREFUSED on the site. I am running in a loop (trying the below script again and again until failure). I know the page I am using is pretty bad quality- that’s why I am using it for testing! My custom timeout will launch, try and then kill chrome between 0 and say 5 times in a row before the error is thrown.

What is irritating, is that I can’t catch this error, which means that sometimes my chrome instance (and the corresponding ~8 processes) doesn’t get killed, even though node has crashed. In my production environment, this will mean that if this happens repeatedly, chrome instances/processes will pile up and eventually choke my server resources! I’d like to be able to catch fatal lighthouse errors and fail gracefully!

node modules:

lighthouse 5.0.0 
chrome-launcher 0.10.7

node wrapper:

const url = 'http://pcfanatics.pk/';

  const chromeFlags = [
    '--headless',
    '--disable-gpu',
    '--no-sandbox',
    '--ignoreHTTPSErrors',
    '--disable-web-security',
    '--incognito',
  ];

  const chrome = await (chromeLauncher.launch)({chromeFlags: chromeFlags});
  const port = chrome.port;

  const lhFlags = {
    disableDeviceEmulation: true,
    disableStorageReset: true,
    throttlingMethod: 'provided',
    maxWaitForLoad: process.env.MAX_WAIT_FOR_LOAD,
    port: port,
    logLevel: 'info',
  };

  const timer = setTimeout(async () => {
    await chrome.kill().then(()=>{
      console.log('Chrome has been killed');
    });
  }, 20000).unref();

  const tryLighthouse = async () => {
    try {
      const result = await lighthouse(url, lhFlags, require('../../lighthouseConfig'));
      return result;
    } catch (e) {
      console.error(e.stack||e);
    }
  };

  const result = await tryLighthouse();

Failure log:

 Driver:warn Timed out waiting for page load. Checking if page is hung... +15s
  Driver:warn Page appears to be hung, killing JavaScript... +2ms
  status Disconnecting from browser... +1ms
Error: not opened
    at WebSocket.send (C:\Users\misha\upugo\upugo-lighthouse-audits\node_modules\ws\lib\WebSocket.js:344:18)
    at CriConnection.sendRawMessage (C:\Users\misha\upugo\upugo-lighthouse-audits\node_modules\lighthouse\lighthouse-core\gather\connections\cri.js:172:14)
    at CriConnection.sendCommand (C:\Users\misha\upugo\upugo-lighthouse-audits\node_modules\lighthouse\lighthouse-core\gather\connections\connection.js:65:10)
    at Driver._innerSendCommand (C:\Users\misha\upugo\upugo-lighthouse-audits\node_modules\lighthouse\lighthouse-core\gather\driver.js:310:29)
    at Promise (C:\Users\misha\upugo\upugo-lighthouse-audits\node_modules\lighthouse\lighthouse-core\gather\driver.js:284:35)
    at new Promise (<anonymous>)
    at Driver.sendCommand (C:\Users\misha\upugo\upugo-lighthouse-audits\node_modules\lighthouse\lighthouse-core\gather\driver.js:275:12)
    at C:\Users\misha\upugo\upugo-lighthouse-audits\node_modules\lighthouse\lighthouse-core\gather\driver.js:878:22
events.js:167
      throw er; // Unhandled 'error' event
      ^

Error: connect ECONNREFUSED 127.0.0.1:56011
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1113:14)
Emitted 'error' event at:
    at Socket.socketErrorListener (_http_client.js:391:9)
    at Socket.emit (events.js:182:13)
    at Socket.EventEmitter.emit (domain.js:442:20)
    at emitErrorNT (internal/streams/destroy.js:82:8)
    at emitErrorAndCloseNT (internal/streams/destroy.js:50:3)
    at process._tickCallback (internal/process/next_tick.js:63:19)

[patrickhulce]

Are you 100% positive this is with lighthouse 5.0?

This was a known bug in 4.x and should be fixed by https://github.com/GoogleChrome/lighthouse/pull/8583. Additionally, the stack trace in your error message points to sendRawMessage at its line count in 4.x. In 5.0 the line referenced by your stack trace points to the end of the file.

[patrickhulce]

Glad we got it sorted out! Feel free to circle back around and re-open if 5.0 still poses this problem