When would an error "Cannot find context with specified id undefined" happen?

I am getting the following error:

Error: Protocol error (Runtime.callFunctionOn): Cannot find context with specified id undefined
    at Session._onMessage (/srv/node_modules/puppeteer-edge/lib/Connection.js:205:25)
    at Connection._onMessage (/srv/node_modules/puppeteer-edge/lib/Connection.js:105:19)
    at emitOne (events.js:115:13)
    at WebSocket.emit (events.js:210:7)
    at Receiver._receiver.onmessage (/srv/node_modules/ws/lib/WebSocket.js:143:47)
    at Receiver.dataMessage (/srv/node_modules/ws/lib/Receiver.js:389:14)
    at Receiver.getData (/srv/node_modules/ws/lib/Receiver.js:330:12)
    at Receiver.startLoop (/srv/node_modules/ws/lib/Receiver.js:165:16)
    at Receiver.add (/srv/node_modules/ws/lib/Receiver.js:139:10)
    at Socket._ultron.on (/srv/node_modules/ws/lib/WebSocket.js:139:22)
    at emitOne (events.js:115:13)
    at Socket.emit (events.js:210:7)
    at addChunk (_stream_readable.js:266:12)
    at readableAddChunk (_stream_readable.js:253:11)
    at Socket.Readable.push (_stream_readable.js:211:10)
    at TCP.onread (net.js:585:20)

It is a large codebase and it is unclear whats triggering this error.

Any guides?

On that note, there needs to be a better way to throw error. Without knowing the origin of the error in the code it is impossible to trace down these exceptions.

[jakub300]

Hi, encountered this problem when updating code that was using puppeteer < 1.0 to newest version. I was also able to find source of the problem.

First, my reproduction script

const puppeteer = require('puppeteer');
let page;

const sleep = (time) => new Promise(resolve => setTimeout(resolve, time));

function wait() {
  page
    .waitForSelector('body')
    .then(() => {
      wait();
    })
    .catch(e => {});
}

(async () => {
  const browser = await puppeteer.launch();
  page = await browser.newPage();
  wait();
  for(let i = 0; i < 10; i += 1) {
    await sleep(1000);
    await page.goto('http://example.com/');
  }
  await browser.close();
})().catch(e => {});

with error:

(node:47660) UnhandledPromiseRejectionWarning: Error: Protocol error (Runtime.callFunctionOn): Cannot find context with specified id undefined
    at Promise (/Users/jakubbogucki/Projects/GeneratorChisel/puppeteer-test/node_modules/puppeteer/lib/Connection.js:200:56)
    at new Promise (<anonymous>)
    at CDPSession.send (/Users/jakubbogucki/Projects/GeneratorChisel/puppeteer-test/node_modules/puppeteer/lib/Connection.js:199:12)
    at ExecutionContext.evaluateHandle (/Users/jakubbogucki/Projects/GeneratorChisel/puppeteer-test/node_modules/puppeteer/lib/ExecutionContext.js:79:75)
    at ExecutionContext.evaluate (/Users/jakubbogucki/Projects/GeneratorChisel/puppeteer-test/node_modules/puppeteer/lib/ExecutionContext.js:46:31)
    at Frame.evaluate (/Users/jakubbogucki/Projects/GeneratorChisel/puppeteer-test/node_modules/puppeteer/lib/FrameManager.js:326:20)
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:188:7)

Please note that it doesn’t happen every time so I added the loop, but possibly 10 runs may be not enough.

End the source of the problem is that line: https://github.com/GoogleChrome/puppeteer/blob/808bf8e5582482a1d849ff22a51e52024810905c/lib/FrameManager.js#L875 You can replace evaluation with

this._frame.evaluate(s => !s, success).catch(e => {})

If you look at rerun function as a whole you will see that earlier it is wrapping evaluation in try/catch and handles errors but that evaluation is not protected in any way. Ironically later there is check for Cannot find context with specified id but it is never reached if second evaluation fails.

/cc @JoelEinbinder @aslushnikov author and reviewer of #1746 that introduced the problematic line

[gajus]

Then why not release 0.14.0? Like, now.

There is literally no reason whatsoever not to automate the releases. There is no reason whatsoever not to release a new version every time a PR has been merged into the master. If you merge something into the master, then it is ready for the release.