Puppeteer browser.close() hangs on AWS Lambda

[doteric]

Hello 👋

I have been having a problem running MemLab in an AWS Lambda (NodeJS v18) timing out no matter what time it is given and decided to investigate what's wrong. After a bit of investigation trying with and wihtout the warmup it looked like MemLab does all the needed work, but just fails to finish off and end, looked into it further and it seems to be an exact same problem that I had somewhere else with puppeteer.
Sparticuz/chromium#85 (comment)
The issue was that the browser can not close properly for some reason, but when all the pages are closed beforehand then it closes all fine. However this is not the case in this situation and I am still experiencing the browser.close() hanging even with the following code of MemLab:

async function closePuppeteer(
  browser: Browser,
  pages: Page[],
  options: AnyOptions = {},
): Promise<void> {
  if (config.isLocalPuppeteer && !options.warmup) {
    await Promise.all(pages.map(page => page.close()));
    await browser.disconnect();
  } else {
    const allPages = await browser.pages();
    for (const page of allPages) {
      await page.close();
    }
    await browser.close();
  }
}

Any other ideas what could be wrong?

To add to this I could not use the defined pages as the passed array is [page] (inside testInBrowser) and does not include any other pages (not expected, but possible) therefore it is safer to just look for all the pages again with await browser.pages()

Puppeteer chromium flags just FYI if they would matter by any chance (one part from MemLab, other part from @sparticuz/chromium.

memlabConfig.puppeteerConfig.args [
  '--no-sandbox',
  '--disable-notifications',
  '--use-fake-ui-for-media-stream',
  '--use-fake-device-for-media-stream',
  '--js-flags="--no-move-object-start"',
  '--enable-precise-memory-info',
  'browser-test',
  '--allow-pre-commit-input',
  '--disable-background-networking',
  '--disable-background-timer-throttling',
  '--disable-backgrounding-occluded-windows',
  '--disable-breakpad',
  '--disable-client-side-phishing-detection',
  '--disable-component-extensions-with-background-pages',
  '--disable-component-update',
  '--disable-default-apps',
  '--disable-dev-shm-usage',
  '--disable-extensions',
  '--disable-hang-monitor',
  '--disable-ipc-flooding-protection',
  '--disable-popup-blocking',
  '--disable-prompt-on-repost',
  '--disable-renderer-backgrounding',
  '--disable-sync',
  '--enable-automation',
  '--enable-blink-features=IdleDetection',
  '--export-tagged-pdf',
  '--force-color-profile=srgb',
  '--metrics-recording-only',
  '--no-first-run',
  '--password-store=basic',
  '--use-mock-keychain',
  '--disable-domain-reliability',
  '--disable-print-preview',
  '--disable-speech-api',
  '--disk-cache-size=33554432',
  '--mute-audio',
  '--no-default-browser-check',
  '--no-pings',
  '--single-process',
  '--disable-features=Translate,BackForwardCache,AcceptCHFrame,MediaRouter,OptimizationHints,AudioServiceOutOfProcess,IsolateOrigins,site-per-process',
  '--enable-features=NetworkServiceInProcess2,SharedArrayBuffer',
  '--hide-scrollbars',
  '--ignore-gpu-blocklist',
  '--in-process-gpu',
  '--window-size=1920,1080',
  '--use-gl=angle',
  '--use-angle=swiftshader',
  '--allow-running-insecure-content',
  '--disable-setuid-sandbox',
  '--disable-site-isolation-trials',
  '--disable-web-security',
  '--no-sandbox',
  '--no-zygote',
  "--headless='new'"
]

[JacksonGL]

"--headless='new'" - Not 100% sure if this is the problem, but this seems to be the new headless mode that puppeteer is testing. Could you try --headless=true and see if the browser can close without hanging (with your code that closes all the pages before closing the browser)?

[doteric]

Thanks @JacksonGL for the idea 💪
Sadly --headless=true + closing all pages before closing the browser does not seem to fix the issue with browser.close() hanging.
For now I will introduce a bypass to waiting for browser.close() to finish, but of course it's far from ideal so if you have any other ideas what could be wrong then I would highly appreciate it 🙇