Playwright: UnhandledPromiseRejectionWarning: Error: Failed to launch browser!

[joshsaintjacque]

First of all, thanks for the work on this project! The prospect of a more platform-agnostic alternative to Puppeteer is exciting.

I'm trying to run the example project locally and ran into an issue, hoping maybe someone can point me in the right direction.

The issue

I have a file, test.ts:

const pw = require('playwright');

(async () => {
  const browser = await pw.firefox.launch({ headless: false }); // 'webkit', 'chromium', 'firefox'
  const context = await browser.newContext();
  const page = await context.newPage();

  await page.goto('https://www.example.com/');
  await page.screenshot({ path: 'example.png' });

  await browser.close();
})();

When I run node test.ts I get the following error:

 UnhandledPromiseRejectionWarning: Error: Failed to launch browser!


TROUBLESHOOTING: https://github.com/Microsoft/playwright/blob/master/docs/troubleshooting.md

    at onClose (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/server/processLauncher.js:135:20)
    at Interface.helper_1.helper.addEventListener (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/server/processLauncher.js:128:65)
    at Interface.emit (events.js:202:15)
    at Interface.close (readline.js:395:8)
    at Socket.onend (readline.js:173:10)
    at Socket.emit (events.js:202:15)
    at endReadableNT (_stream_readable.js:1129:12)
    at processTicksAndRejections (internal/process/next_tick.js:76:17)
  -- ASYNC --
    at FFPlaywright.<anonymous> (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/helper.js:54:23)
    at FFPlaywright.launch (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/server/ffPlaywright.js:63:35)
    at FFPlaywright.<anonymous> (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/helper.js:55:31)
    at /mnt/c/Users/joshs/repos/Bullet/api/test.ts:4:36
    at Object.<anonymous> (/mnt/c/Users/joshs/repos/Bullet/api/test.ts:12:3)
    at Module._compile (internal/modules/cjs/loader.js:734:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:745:10)
    at Module.load (internal/modules/cjs/loader.js:626:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:566:12)
    at Function.Module._load (internal/modules/cjs/loader.js:558:3)    
  -- ASYNC --
    at FFPlaywright.<anonymous> (/mnt/c/Users/joshs/repos/Bullet/api/node_modules/playwright-core/lib/helper.js:54:23)
    at /mnt/c/Users/joshs/repos/Bullet/api/test.ts:4:36
    at Object.<anonymous> (/mnt/c/Users/joshs/repos/Bullet/api/test.ts:12:3)
    at Module._compile (internal/modules/cjs/loader.js:734:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:745:10)
    at Module.load (internal/modules/cjs/loader.js:626:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:566:12)
    at Function.Module._load (internal/modules/cjs/loader.js:558:3)    
    at Function.Module.runMain (internal/modules/cjs/loader.js:797:12) 
    at executeUserCode (internal/bootstrap/node.js:526:15)
(node:9422) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:9422) [DEP0018] DeprecationWarning: Unhandled promise rejections 
are deprecated. In the future, promise rejections that are not handled 
will terminate the Node.js process with a non-zero exit code.

What I'm running

I'm running WSL on Windows 10, Node 11.9.0.

What I've tried

I had similar code integrated more deeply into an application I'm working on. I pulled the code out into the simplest reproducible case I could, which is the code above.

I've tried switching between firefox, chromium, and webkit. I've also tried setting headless to false.

Any help or guidance you might be able to offer is appreciated!

[JoelEinbinder]

Thanks for joining us on the bleeding edge!

Did you run both npm install and node test.ts from within WSL? Installing from windows but running from within WSL, or vice versa, would probably cause this error.

Assuming your WSL is Ubuntu based, you probably need to get Chrome's dependencies. It looks like we are missing the list of what those dependencies actually are, but I'd try

sudo apt install \
    gconf-service \
    libasound2 \
    libatk1.0-0 \
    libatk-bridge2.0-0 \
    libc6 \
    libcairo2 \
    libcups2 \
    libdbus-1-3 \
    libexpat1 \
    libfontconfig1 \
    libgcc1 \
    libgconf-2-4 \
    libgdk-pixbuf2.0-0 \
    libglib2.0-0 \
    libgtk-3-0 \
    libnspr4 \
    libpango-1.0-0 \
    libpangocairo-1.0-0 \
    libstdc++6 \
    libx11-6 \
    libx11-xcb1 \
    libxcb1 \
    libxcomposite1 \
    libxcursor1 \
    libxdamage1 \
    libxext6 \
    libxfixes3 \
    libxi6 \
    libxrandr2 \
    libxrender1 \
    libxss1 \
    libxtst6 \
    ca-certificates \
    fonts-liberation \
    libappindicator1 \
    libnss3 \
    lsb-release \
    xdg-utils \
    wget

You can also launch with the dumpio: true option, to see if there is something helpful being logged by the browser itself.

[joshsaintjacque]

@JoelEinbinder Thanks for your timely response!

I was able to track down the issue. The problem appears to be with Chromium's sandbox. I found some troubleshoot docs from Puppeteer that gave the hint.

I've been unable to get a Chrome sandbox on WSL, but if I disable sandbox (which isn't ideal) it does work:

const browser = await pw.chromium.launch({ args: ['--no-sandbox', '--disable-setuid-sandbox'] });

Edit: I should note that this only works for Chromium. Firefox continues to throw the cryptic UnhandledPromiseRejectionWarning: Error: Failed to launch browser!.

I'm able to get a little more out of Webkit, it throws:

UnhandledPromiseRejectionWarning: Error: Failed to launch browser: Error: spawn /mnt/c/Users/joshs/repos/pw-test/node_modules/playwright-core/.local-webkit/linux-1106/pw_run.sh ENOENT
    at ChildProcess.spawnedProcess.once.error (/mnt/c/Users/joshs/repos/pw-test/node_modules/playwright-core/lib/server/processLauncher.js:49:20)
    at Object.onceWrapper (events.js:285:13)
    at ChildProcess.emit (events.js:197:13)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:252:12)
    at onErrorNT (internal/child_process.js:421:16)
    at processTicksAndRejections (internal/process/next_tick.js:76:17)
  ...

[butlersrepos]

@JoelEinbinder Those helped me over this hurdle but just wanted to point out that a preliminary

sudo apt-get update

may be needed

[FezVrasta]

I get the same Error: Chromium revision is not downloaded. Run "npm install" at Chromium.launchBrowserApp (/home/travis/build/popperjs/popper-core/node_modules/playwright-core/lib/server/chromium.js:70:23) on macOS and Travis, the only solution is to delete node_modules and yarn again.

[FezVrasta]

To add more details, it seems to be a problem with Yarn. npm seems to reliably download the browser binaries every time.

[tyler-graham-ck]

In the meantime it appears that running node ./node_modules/playwright/install.js before executing your tests will download the binaries if necessary

[pavelfeldman]

Folding this into https://github.com/microsoft/playwright/issues/581 and https://github.com/microsoft/playwright/issues/1085

[pavelfeldman]

Folding into https://github.com/microsoft/playwright/issues/1103