Cypress: Look into adding `--disable-dev-shm-usage` Chrome flag

[flotwig]

Current behavior:

Cypress doesn't pass --disable-dev-shm-usage: https://github.com/cypress-io/cypress/blob/develop/packages/server/lib/browsers/chrome.coffee#L21

But Puppeteer does: https://github.com/GoogleChrome/puppeteer/blob/master/lib/Launcher.js#L37

However, in this commit that adds --disable-dev-shm-usage, it seems to cause failures to start Chrome: 7247dcfa78ad3e1d0ad032474e724a083007edda

It may be because Cypress does not run Chrome headlessly: #832

Desired behavior:

Cypress passes --disable-dev-shm-usage so that machines with small /dev/shms can run Cypress.

Original issue: #3633

Workaround (4.0.0 and up)

A user can modify Chrome flags by adding this in their pluginsfile:

module.exports = (on, config) => {
  on('before:browser:launch', (browser = {}, launchOptions) => {
    if (browser.family === 'chrome') {
      console.log('Adding --disable-dev-shm-usage...')
      launchOptions.args.push('--disable-dev-shm-usage')
    }

    return launchOptions
  })
}

Workaround (pre-4.0.0)

A user can modify Chrome flags by adding this in their pluginsfile:

module.exports = (on, config) => {
  on('before:browser:launch', (browser = {}, args) => {
    if (browser.family === 'chromium') {
      console.log('Adding --disable-dev-shm-usage...')
      args.push('--disable-dev-shm-usage')
    }

    return args
  })
}

Edited by @jennifer-shehane to note browser.family to equal chromium

[Jacek-fstack]

Did anyone else notice that this command is not working for the new chrome (80)? I upgraded my chrome and the chrome crashes, just like in earlier versions, before this code.

[flotwig]

Updated the workaround in the OP for Cypress 4.0.0+.

@Jacek-fstack so Chrome 80 successfully launches with --disable-dev-shm-usage, but eventually crashes? Is there an error?

[Jazzepi]

I was getting this error constantly during normal usage. Usually from doing things like alt-tabbing. I was using the electron version, not chrome, to launch Cypress.

FATAL:memory.cc(22)] Out of memory. size=262144

However, I was running Cypress itself inside of a Docker container. I ended up solving this by mounting the shm directory --volume=/dev/shm:/dev/shm so that the docker container had access to all the shm the host machine has available.

[dragon788]

On macOS there is no /dev/shm to map in, but you can use --shm-size=1gb to accomplish the same task in a cross platform manner. You can adjust the size a bit, especially considering the default is a measly 64mb.

[adamalton]

Note that in the workaround from @flotwig above, the browser.family should be compared to 'chromium' not 'chrome'.

[jennifer-shehane]

@adamalton Thanks! I've updated the original comment to reflect this.

[cypress-bot[bot]]

The code for this is done in cypress-io/cypress#9242, but has yet to be released.
We'll update this issue and reference the changelog when it's released.

[cypress-bot[bot]]

Released in 6.0.0.

This comment thread has been locked. If you are still experiencing this issue after upgrading to
Cypress v6.0.0, please open a new issue.