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Troubleshooting

There are times when you will encounter errors or unexpected behavior with Cypress itself. This guide recommends some resources and steps to take to troubleshoot those problems.

Update Cypress​

We always recommend using the latest version of Cypress. If you're not using the latest version, upgrade to the latest version. Your issue may already be resolved.

Support channels​

Check these support resources:

  • Connect with our community in Discord
  • Search existing GitHub issues
  • Search this documentation (search is in the top right) 😉
  • Search Stack Overflow for relevant answers
  • If your organization signs up for one of our paid plans, you can get dedicated email support, which gives you one-on-one help from our team.
  • If you still haven't found a solution, open an issue with a reproducible example.

Common GitHub issues​

Below are some of common problem topics users experience with a link to the main issue(s) and links to the open and closed issues in the topic. Maybe you can find an open or closed issue matching your problem. Even open issues might suggest a workaround or shed more information on the problem.

LabelDescriptionIssues
browser detectionLocal browser is not detectedopen, closed
cross-originGetting cross-origin erroropen, closed
cy.requestIssues related to cy.request() commandopen, closed
fixturesFixture loading and usageopen, closed
hooksIssues related to hooksopen, closed
iframesWorking with iframesopen, closed
installationCypress cannot be downloaded or installedopen, closed
networkControlling network requestsopen, closed
performanceSlow loading, slow network, etcopen, closed
screenshotsTaking image screenshotsopen, closed
scrollingScrolling elements into viewopen, closed
spec executionRunning all or filtered specsopen, closed
test executionRunning tests inside a single specopen, closed
TypeScriptTranspiling or bundling TypeScriptopen, closed
videoProblems with video recordingsopen, closed
file downloadsFile downloads are not workingopen, closed
interceptNetwork stubbing using cy.interceptopen, closed
SIG* errorsCrashes with errors like SIGSEGVopen, closed
environment variablesParsing and using environment variablesopen, closed

Isolate the Problem​

When debugging a failing test, follow these general principles to isolate the problem:

  • Look at the video recordings and screenshots.
  • Split large spec files into smaller ones.
  • Split long tests into smaller tests.
  • Run the same test using --browser chrome. The problem might be isolated to the Electron browser.
  • If isolated to the Electron browser. Run the same tests in both Electron and Chrome, then compare the screenshots/videos. Look for and isolate any differences in the Command Log.

Download specific Chrome version​

The Chrome browser is evergreen - meaning it will automatically update itself, sometimes causing a breaking change in your automated tests. You can use the information in Download Chromium to download a specific released version of Chromium for every platform.

Clear Cypress cache​

If you're having an issue during installation of Cypress, try removing the contents of the Cypress cache.

This will clear out all installed versions of Cypress that may be cached on your machine.

cypress cache clear

After running this command, you will need to run cypress install before running Cypress again.

npm install cypress --save-dev

Launching browsers​

Cypress attempts to automatically find installed Chrome versions for you. However, probing for browsers across different environments can be error-prone. If Cypress cannot find a browser but you know you have it installed, there are ways to ensure that Cypress can "see" it.

info
Using the --browser command line argument

You can also supply the --browser command line argument to launch a browser from a known filesystem path to bypass browser auto detection. See 'Launching Browsers' for more information

You can see the full list of found browsers and their properties within the resolved configuration in the Settings tab of Cypress.

Another way to log what is found by Cypress is to run Cypress with the DEBUG environment variable set to cypress:launcher:*. This will print information about the found browsers and their properties to the terminal.

Tip: use the cypress info command to see all locally detected browsers.

Mac​

On Mac, Cypress attempts to find installed browsers by their bundle identifier. If this does not succeed, it will fall back to the Linux browser detection method.

Browser NameExpected Bundle IdentifierExpected Executable
chromecom.google.ChromeContents/MacOS/Google Chrome
chromiumorg.chromium.ChromiumContents/MacOS/Chromium
chrome:canarycom.google.Chrome.canaryContents/MacOS/Google Chrome Canary

For the current list, see packages/launcher files.

Linux​

On Linux, Cypress scans your PATH for a number of different binary names. If the browser you are trying to use does not exist under one of the expected binary names, Cypress will not be able to find it.

Browser NameExpected Binary Name(s)
chromegoogle-chrome, chrome, or google-chrome-stable
chromiumchromium-browser or chromium
chrome:canarygoogle-chrome-canary

These binary names should work for most Linux distributions. If your distribution packages browsers under a different binary name, you can add a symlink using the expected binary name so that Cypress can detect it.

For example, if your distribution packages Google Chrome as chrome, you could add a symlink to google-chrome like this:

sudo ln `which chrome` /usr/local/bin/google-chrome

Windows​

On Windows, Cypress scans the following locations to try to find each browser:

Browser NameExpected Path
chromeC:/Program Files (x86)/Google/Chrome/Application/chrome.exe
chromiumC:/Program Files (x86)/Google/chrome-win32/chrome.exe
chrome:canary%APPDATA%/../Local/Google/Chrome SxS/Application/chrome.exe

For the current list, see packages/launcher files.

To make a browser installed at a different path be auto-detected, create a symbolic link using mklink in the location that Cypress expects to find your browser.

Read more about creating symbolic links on Windows

Occasionally Cypress will have issues detecting the type of browser in Windows environments. To manually detect the browser type, append the browser type to the end of the path:

cypress open --browser C:/User/Application/browser.exe:chrome

Allow the Cypress Chrome extension​

Cypress utilizes a Chrome extension in order to run properly. If you or your company block specific Chrome extensions, this may cause problems with running Cypress. You will want to ask your administrator to allow the Cypress extension ID below:

caljajdfkjjjdehjdoimjkkakekklcck

You can check the current company policies for your Chrome installation by typing chrome://policy into the address bar and pressing Enter.

Allow Cypress URLs on VPNs​

To send the data and results of your tests to Cypress Cloud, Cypress needs free access to some URLs.

If you are running the tests from within a restrictive VPN you will need to allow some URLs so that Cypress can have effective communication with Cypress Cloud.

The URLs are the following:

  • https://api.cypress.io - Cypress API
  • https://assets.cypress.io - Asset CDN (Org logos, icons, videos, screenshots, etc.)
  • https://authenticate.cypress.io - Authentication API
  • https://capture.cypress.io - Cypress Test Replay
  • https://s3.amazonaws.com/capture.cypress.io - Uploading Cypress Test Replay from Test Runner
  • https://cloud.cypress.io - Cypress Cloud
  • https://docs.cypress.io - Cypress documentation
  • https://download.cypress.io - CDN download of Cypress binary
  • https://on.cypress.io - URL shortener for link redirects

If you are using GitHub Enterprise or GitLab for Enterprise (Self-managed), you may also need to add the following to the version control IP allowlist:

  • 3.211.102.119 - Dedicated IP
  • 18.213.72.78 - Dedicated IP
  • 35.169.145.173 - Dedicated IP
  • 44.199.152.70 - Dedicated IP
  • 52.70.95.89 - Dedicated IP

Clear App Data​

Cypress maintains some local application data in order to save user preferences and more quickly start up. Sometimes this data can become corrupted. You may fix an issue you have by clearing this app data.

To clear App Data​

  1. Open Cypress via cypress open
  2. Go to Developer Tools -> View App Data
  3. This will take you to the directory in your file system where your App Data is stored. If you cannot open Cypress, search your file system for a directory named cy whose content should look something like this:
📂 production
  📄 all.log
  📁 browsers
  📁 bundles
  📄 cache
  📁 projects
  📁 proxy
  📄 state.json
  1. Delete everything in the cy folder
  2. Close Cypress and open it up again

Cypress utilizes the debug module. That means you can receive helpful debugging output by running Cypress with a system-level environment variable DEBUG set to cypress:* prior to running cypress run or cypress open.

tip

Enabling debug output can generate a large amount of data. This may also impact performance. Only enable debug output when you need it.

To reduce the amount of debug output data generated, replace cypress:* using a more selective value for DEBUG. See below, including the section Log sources.

If you need to share debug output collected in a file, consider first compressing it with a ZIP utility or similar to reduce the file size before sharing.

On macOS, Linux or Windows (Git Bash):

DEBUG=cypress:* npx cypress run

You can change run to open in the above to capture debug logs when starting your tests from the Cypress Specs UI.

For non-POSIX type shells on Windows, set the DEBUG environment variable as follows. (Replace npx with yarn or pnpm if you are using Yarn or pnpm package managers instead of npm.)

On Windows CMD:

set DEBUG=cypress:*
npx cypress run

On Windows PowerShell:

$env:DEBUG='cypress:*'
npx cypress run

If you have issues with the logs not printing, it may be a permissions issue with setting the environment variable in your terminal. You may need to run your terminal in administrative mode or review your permission settings.

How to run Cypress CLI commands provides background information on running Cypress from the command line and includes a reference of additional command line options.

Read more: Good Logging blog post.

Detailed Logs​

There are several levels of DEBUG messages

## prints very few top-level messages
DEBUG=cypress:server ...
## prints ALL messages from server package
DEBUG=cypress:server* ...
## prints messages only from project base operations
DEBUG=cypress:server:project ...

This allows you to isolate the problem a little better

Log sources​

Cypress is built from multiple packages, each responsible for its own logging: server, reporter, driver, command line, etc. Each package writes debug logs under a different source. Here are a few common log sources and when you might want to enable them

Set DEBUG to valueTo enable debugging
cypress:*ALL modules
cypress:cli*Top-level command line parsing and binary installation
cypress:server:argsIncorrect parsed command line arguments
cypress:data-context:sources:*Not finding the expected project data
cypress:server:projectOpening the project
cypress:server:browsers*Finding installed browsers
cypress:launcher:*Launching the found browser
cypress:server:videoVideo recording
cypress:network:*Adding network interceptors
cypress:net-stubbing:*Network interception in the proxy layer
cypress:server:reporterProblems with test reporters
cypress:server:preprocessorProcessing specs
cypress:server:socket-e2eWatching spec files
cypress:server:taskInvoking the cy.task() command
cypress:server:socket-baseDebugging cy.request() command
cypress:webpackBundling specs using webpack
cypress:server:fixtureLoading fixture files
cypress:server:record:ci-infoGit commit and CI information when recording to Cypress Cloud

You can combine several areas together using the comma character. For example, to debug specs not being found, use:

## see how CLI arguments were parsed
## and how Cypress tried to locate spec files
DEBUG=cypress:cli,cypress:data-context:sources:FileDataSource,cypress:data-context:sources:ProjectDataSource npx cypress run --spec ...

You can also exclude a log source using the - character. For example, to see all cypress:server* messages without noisy browser messages use:

DEBUG=cypress:server*,-cypress:server:browsers* npx cypress run

Debug log depth​

Sometimes the logged object has deeply nested properties and is shown as [Object] instead of the full serialization.

DEBUG=cypress:server:socket-base npx cypress run

cypress:server:socket-base backend:request { eventName: 'http:request', args:
  [ { url: 'http://localhost:7065/echo', method: 'POST', body: [Object], auth: [Object],
  json: true, encoding: 'utf8', gzip: true, timeout: 30000, followRedirect: true,
  failOnStatusCode: true, retryOnNetworkFailure: true,
  retryOnStatusCodeFailure: false } ] } +5ms

You can increase the printed object depth using the DEBUG_DEPTH environment variable

DEBUG=cypress:server:socket-base DEBUG_DEPTH=3 npx cypress run

cypress:server:socket-base backend:request { eventName: 'http:request', args:
  [ { url: 'http://localhost:7065/echo', method: 'POST', body: { text: 'ping!' },
  auth: { username: 'jane.lane', password: 'password123' }, json: true, encoding: 'utf8',
  gzip: true, timeout: 30000, followRedirect: true, failOnStatusCode: true,
  retryOnNetworkFailure: true, retryOnStatusCodeFailure: false } ] } +4ms

3rd party modules​

Some 3rd party modules like @cypress/request output additional log messages by inspecting the NODE_DEBUG environment variable. For example to debug the network interception and the requests made by the @cypress/request module use:

DEBUG=cypress:net-stubbing:server:intercept-request \
  NODE_DEBUG=request npx cypress run

Debug logs in the browser​

If the problem is seen during cypress open you can print debug logs in the browser too. Open the browser's Developer Tools and set a localStorage property:

localStorage.debug = 'cypress*'

// to disable debug messages
delete localStorage.debug

Reload the browser and turn on 'Verbose' logs to see debug messages within the Developer Tools console. You will only see the cypress:driver package logs that run in the browser, as you can see below.

Debug logs in browser

Log memory and CPU usage​

You can tell Cypress to log out a summary of the memory and CPU usage of itself and any subprocesses at a regular interval by enabling the cypress:server:util:process_profiler debug stream, like so:

DEBUG=cypress:server:util:process_profiler npx cypress run

(See Print DEBUG Logs above for hints on setting the DEBUG environment variable in a non-POSIX Windows terminal.)

In the resulting output, processes are grouped by their name.

Process printout of Cypress in CLI

By default, process information is collected, summarized and is printed once every 10 seconds. You can override this interval by setting the CYPRESS_PROCESS_PROFILER_INTERVAL environment variable to the desired interval in milliseconds.

You can also obtain more detailed per-process information by enabling the verbose cypress-verbose:server:util:process_profiler debug stream.

Disable the Command Log​

In some cases the Command Log, responsible for displaying test commands, assertions, and statuses in the Cypress Test Runner, may cause performance issues resulting in slower tests or the browser crashing.

In order to isolate these issues, you can hide the Command Log by passing the environment variable below during cypress open or cypress run.

CYPRESS_NO_COMMAND_LOG=1 cypress run

You can also hide the entire Cypress Runner UI in cypress run by passing the --no-runner-ui command line flag.

npx cypress run --no-runner-ui

With this variable set, Cypress will skip rendering the Command Log entirely, and perform none of the usual DOM updates to display information about commands and statuses as the test runs.

Note: With this variable set, screenshots and videos will not include the Command Log.

Additional information​

Write command log to the terminal​

You can include the plugin cypress-failed-log in your tests. This plugin writes the list of Cypress commands to the terminal as well as a JSON file if a test fails.

cypress-failed-log terminal output

Hacking on Cypress​

If you want to dive into Cypress and edit the code yourself, you can do that. The Cypress code is open source and licensed under an MIT license. There are a few tips on getting started that we've outlined below.

Contribute​

If you'd like to contribute directly to the Cypress code, we'd love to have your help! Please check out our contributing guide to learn about the many ways you can contribute.

Run Cypress by itself​

Cypress comes with an npm CLI module that parses the arguments, starts the Xvfb server (if necessary), and then opens Cypress.

Some common situations on why you would want to run Cypress by itself are to:

  • debug Cypress not starting or hanging
  • debug problems related to the way CLI arguments are parsed by the npm CLI module

Here is how you can launch Cypress directly without the npm CLI module. First, find where the binary is installed using the cypress cache path command.

For example, on a Linux machine:

npx cypress cache path
/root/.cache/Cypress

Second, try a smoke test that verifies that the application has all its required dependencies present on the host machine:

/root/.cache/Cypress/3.3.1/Cypress/Cypress --smoke-test --ping=101
101

If there is a missing dependency, the application should print an error message. You can see the Electron verbose log messages by setting an environment variable ELECTRON_ENABLE_LOGGING:

ELECTRON_ENABLE_LOGGING=true DISPLAY=10.130.4.201:0 /root/.cache/Cypress/3.3.1/Cypress/Cypress --smoke-test --ping=101
[809:0617/151243.281369:ERROR:bus.cc(395)] Failed to connect to the bus: Failed to connect to socket /var/run/dbus/system_bus_socket: No such file or directory
101

If the smoke test fails to execute, check if a shared library is missing (a common problem on Linux machines without all of the Cypress dependencies present).

ldd /home/person/.cache/Cypress/3.3.1/Cypress/Cypress
  linux-vdso.so.1 (0x00007ffe9eda0000)
  libnode.so => /home/person/.cache/Cypress/3.3.1/Cypress/libnode.so (0x00007fecb43c8000)
  libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fecb41ab000)
  libgtk-3.so.0 => not found
  libgdk-3.so.0 => not found
  ...

Tip: use Cypress Docker image or install dependencies by copying them from one of our official Docker images.

Note: verbose Electron logging might show warnings that still allow Cypress to work normally. For example, Cypress opens normally despite the scary output below:

ELECTRON_ENABLE_LOGGING=true DISPLAY=10.130.4.201:0 /root/.cache/Cypress/3.3.1/Cypress/Cypress
[475:0617/150421.326986:ERROR:bus.cc(395)] Failed to connect to the bus: Failed to connect to socket /var/run/dbus/system_bus_socket: No such file or directory
[475:0617/150425.061526:ERROR:bus.cc(395)] Failed to connect to the bus: Could not parse server address: Unknown address type (examples of valid types are "tcp" and on UNIX "unix")
[475:0617/150425.079819:ERROR:bus.cc(395)] Failed to connect to the bus: Could not parse server address: Unknown address type (examples of valid types are "tcp" and on UNIX "unix")
[475:0617/150425.371013:INFO:CONSOLE(73292)] "%cDownload the React DevTools for a better development experience: https://fb.me/react-devtools
You might need to use a local HTTP server (instead of file://): https://fb.me/react-devtools-faq", source: file:///root/.cache/Cypress/3.3.1/Cypress/resources/app/packages/desktop-gui/dist/app.js (73292)

You can also see verbose Cypress logs when running the Cypress binary

DEBUG=cypress* DISPLAY=10.130.4.201:0 /root/.cache/Cypress/3.3.1/Cypress/Cypress --smoke-test --ping=101
cypress:ts Running without ts-node hook in environment "production" +0ms
cypress:server:cypress starting cypress with argv [ '/root/.cache/Cypress/3.3.1/Cypress/Cypress', '--smoke-test', '--ping=101' ] +0ms
cypress:server:args argv array: [ '/root/.cache/Cypress/3.3.1/Cypress/Cypress', '--smoke-test', '--ping=101' ] +0ms
cypress:server:args argv parsed: { _: [ '/root/.cache/Cypress/3.3.1/Cypress/Cypress' ], smokeTest: true, ping: 101, cwd: '/root/.cache/Cypress/3.3.1/Cypress/resources/app/packages/server' } +7ms
cypress:server:args options { _: [ '/root/.cache/Cypress/3.3.1/Cypress/Cypress' ], smokeTest: true, ping: 101, cwd: '/root/.cache/Cypress/3.3.1/Cypress/resources/app/packages/server', config: {} } +2ms
cypress:server:args argv options: { _: [ '/root/.cache/Cypress/3.3.1/Cypress/Cypress' ], smokeTest: true, ping: 101, cwd: '/root/.cache/Cypress/3.3.1/Cypress/resources/app/packages/server', config: {}, pong: 101 } +1ms
cypress:server:appdata path: /root/.config/Cypress/cy/production +0ms
cypress:server:cypress starting in mode smokeTest +356ms
101
cypress:server:cypress about to exit with code 0 +4ms

If the smoke test does not show a specific error yet fails, try printing the Electron crash stack to maybe pinpoint the problem better:

ELECTRON_ENABLE_STACK_DUMPING=1 npx cypress verify
...
Received signal 11 SEGV_MAPERR ffffffb27e8955bb
#0 0x55c6389f83d9 (/root/.cache/Cypress/3.8.2/Cypress/Cypress+0x35d13d8)
r8: 0000000000000000  r9: 00007ffcf0387c80 r10: 00007ffcf0387bd8 r11: 000000000000000e
r12: 00007ffcf0387d2c r13: 00007f3ea737b720 r14: ffffffb27e89558b r15: 00007f3ea8974200
di: 0000000000000000  si: 0000000000000020  bp: 0000000000000000  bx: 0000004f2f375580
dx: 0000000000000001  ax: 0000000000000030  cx: 0000000000000001  sp: 00007ffcf0387d00
ip: 00007f3ea89582dd efl: 0000000000010246 cgf: 002b000000000033 erf: 0000000000000005
trp: 000000000000000e msk: 0000000000000000 cr2: ffffffb27e8955bb
[end of stack trace]
Calling _exit(1). Core file will not be generated.

Patch Cypress​

Cypress comes with an npm CLI module that parses the arguments, starts the Xvfb server (if necessary), and then opens Cypress.

If you're encountering a bug in the current version of Cypress, you can implement a temporary fix by patching Cypress in your own project. Here is an example of how to do this.

  1. Install patch-package.
  2. Add a patch step to your CI configuration after installing your npm packages.
- run: npm ci
- run: npx patch-package

Alternatively, you can apply the patch during a post-install phase. In your package.json, for example, you could add the following:

{
  "scripts": {
    "postinstall": "patch-package"
  }
}
  1. Edit the line causing the problem in your local node_modules folder within node_modules/cypress.
  2. Run the npx patch-package cypress command. This command will create a new file named after the current Cypress version, for example, patches/cypress+13.15.0.patch.
npx patch-package cypress
patch-package 8.0.0
• Creating temporary folder
• Installing cypress@13.15.0 with npm
• Diffing your files with clean files
✔ Created file patches/cypress+13.15.0.patch

💡 cypress is on GitHub! To draft an issue based on your patch run

    npx patch-package cypress --create-issue
  1. Commit the new patches folder to git.
info

If you find a patch for an error, please add a comment to the relevant Cypress GitHub issue explaining your workaround. It can help us release an official fix faster. Alternatively you can use the following command to create a new issue based on your patch contents.

npx patch-package cypress --create-issue

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