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Test Runners

Jest, Vitest, Cypress, Playwright, RSpec - test failures decoded.

Fix test-runner errors in CI: Jest, Vitest, Mocha, Cypress, Playwright, Selenium, RSpec, and PHPUnit - config, timeouts, flakiness, and CI-only failures.

JS test runners

Jest, Vitest, Mocha config & failures.

"worker ... failed to exit gracefully"Fix Jest "A worker process has failed to exit gracefully... a memory leak" in CI - open handles like servers,… "Async callback was not invoked"Fix Jest "Async callback was not invoked within the 5000 ms timeout specified by jest.setTimeout" in CI - a d… "Cannot find module ... from"Fix Jest "Cannot find module 'X' from 'spec.test.ts'" in CI - a missing dependency, an unmapped path alias, o… "Cannot find module"Fix Jest "Cannot find module" in CI - a missing dependency, an unmapped path alias, or a case-sensitive impor… "Cannot log after tests are done"Fix Jest "Cannot log after tests are done. Did you forget to wait for something async?" in CI - async work lo… "Cannot use import statement"Fix Jest "SyntaxError: Cannot use import statement outside a module" in CI - an ESM-only dependency left untr… "coverage threshold ... not met"Fix Jest "Jest: coverage threshold for X not met" failing CI - global vs per-file thresholds, uncovered new c… "coverage threshold ... not met"Fix Jest "Jest: coverage threshold for X not met" in CI - uncovered new code, files excluded from collection,… "Jest did not exit"Fix Jest "Jest did not exit one second after the test run completed" in CI - async operations not stopped. Fi… "Jest did not exit"Fix Jest "A worker process has failed to exit gracefully... Jest did not exit one second after" - open handle… "Jest encountered an unexpected token"Fix Jest "Jest encountered an unexpected token" on TypeScript or JSX syntax in CI - Jest received code its tr… "Exceeded timeout of 5000 ms"Fix Jest "Exceeded timeout of 5000 ms for a test" - a never-resolving promise, a forgotten async return/await… "Exceeded timeout of 5000 ms"Fix Jest "Exceeded timeout of 5000 ms for a test" in CI - a promise that never settles, async not awaited or… "heap out of memory"Fix Jest "FATAL ERROR: ... JavaScript heap out of memory" in CI - too many parallel workers for the runner RA… "Jest encountered an unexpected token"Fix Jest "Jest encountered an unexpected token" in CI - an ESM-only or JSX/TS dependency inside node_modules… "duplicate ... naming collision"Fix Jest "jest-haste-map: Haste module naming collision" and "duplicate manual mock found" in CI - two files… "New snapshot was not written"Fix Jest "New snapshot was not written: The update flag must be explicitly passed" in CI - a brand-new snapsh… "New snapshot was not written"Fix Jest "New snapshot was not written: The update flag must be explicitly passed" in CI - Jest refuses to cr… "N obsolete snapshots found"Fix Jest "obsolete snapshots" failing CI when run with --ci and a strict gate - snapshot keys left behind aft… "ReferenceError: document is not defined"Fix Jest "ReferenceError: document is not defined" in CI - the test environment is node, not jsdom, so browse… "TextEncoder is not defined"Fix Jest jsdom "ReferenceError: TextEncoder is not defined" in CI - a Web API jsdom does not implement. Polyf… "ReferenceError: ... is not defined"Fix Jest "ReferenceError: window/document/TextEncoder is not defined" - wrong testEnvironment, a missing jsdo… "SecurityError: localStorage"Fix Jest jsdom "SecurityError: localStorage is not available for opaque origins" - set a testURL/jsdom URL or… "Cannot use import statement"Fix Jest "SyntaxError: Cannot use import statement outside a module" in CI - an ESM-only dependency not trans… "jest-environment-jsdom cannot be found"Fix Jest "Test environment jest-environment-jsdom cannot be found" after upgrading to Jest 28+ - jsdom is now… CSS/asset import failsFix Jest failing on `import "./styles.css"` or SVG/image imports in CI - map non-JS assets to stubs with modu… "Validation Error" unknown optionFix Jest "Validation Error: Unknown option X was found" in CI - the Jest config contains a key Jest does not… "worker ... child process exceptions"Fix Jest "Jest worker encountered 4 child process exceptions, exceeding retry limit" in CI - usually an out-o… "must contain at least one test"Fix Jest "Your test suite must contain at least one test" in CI - an empty file matched by testMatch, all tes… "must contain at least one test"Fix Jest "Your test suite must contain at least one test" - an empty file matched by testMatch, all tests ski… "Cannot use import" (ESM project)Fix Jest in a "type":"module" ESM project - "Cannot use import statement" or "module is not defined" - by ena… Obsolete snapshot / --ciFix Jest obsolete snapshots and missing-snapshot failures in CI - under --ci Jest will not write new snapshot… setupFilesAfterEnv not loadingFix Jest "expect(...).toBeInTheDocument is not a function" or missing global hooks - a setupFilesAfterEnv pat… "snapshot ... failed"Fix Jest snapshot failures in CI - "received value does not match stored snapshot" or obsolete snapshots, fro… transformIgnorePatterns mis-setFix Jest still failing on an ESM dependency after editing transformIgnorePatterns - a wrong negative-lookahea… Jest --watch hangs in CIFix Jest watch mode hanging in CI - "jest --watch" waits for keypresses on a TTY that CI does not have, so th… JUnit report not generatedFix jest-junit producing no results.xml in CI - the reporter not added to the reporters array, a wrong output… Fake timers stuckFix Jest/Vitest fake-timer tests that hang or time out - fake timers enabled but never advanced, real promise… Order-dependent flakeFix flaky order-dependent JS tests that pass in isolation but fail when run together - shared mutable state,… Mocha "0 passing"Fix Mocha "0 passing" with no tests executed in CI - Mocha ran but matched no test files or no describe/it bl… Mocha "before all" hook failedFix Mocha "before all" hook failures in CI - when a top-level beforeEach/before hook throws, Mocha skips the… "Cannot find module 'ts-node/register'"Fix Mocha "Error: Cannot find module 'ts-node/register'" in CI - ts-node not installed, or required before it… "done() called multiple times"Fix Mocha "Error: done() called multiple times" in CI - a callback invoked twice, mixing done with a returned… "Ensure the done() callback is being called"Fix Mocha "Timeout of 2000ms exceeded ... Ensure the done() callback is being called, or a promise is returne… "No test files found"Fix Mocha "Error: No test files found" in CI - a spec glob that matches nothing, a missing --recursive, or th… "Timeout of 2000ms exceeded"Fix Mocha "Error: Timeout of 2000ms exceeded. For async tests... ensure done() is called" - a missing done(),… "Timeout of 2000ms exceeded"Fix Mocha "Error: Timeout of 2000ms exceeded. For async tests... ensure done() is called" in CI - a missing d… "Cannot find name 'describe'"Fix ts-jest "Cannot find name 'describe'/'it'/'expect'" in CI - the Jest type definitions are not in scope. A… vi.mock hoisting errorFix Vitest vi.mock hoisting errors - "Cannot access X before initialization" / "There are some problems resol… "Failed to load ... coverage provider"Fix Vitest "Cannot find dependency @vitest/coverage-v8" / istanbul in CI - the coverage provider is a separat… "Cannot find package '@vitest/coverage-v8'"Fix Vitest "Cannot find package @vitest/coverage-v8" in CI - the coverage provider is a separate package you… "Cannot find package happy-dom"Fix Vitest "Cannot find package happy-dom" or jsdom in CI - the DOM environment is an optional peer you insta… "Cannot find package 'jsdom'"Fix Vitest "Cannot find package jsdom" / "Failed to load environment jsdom" in CI - the jsdom environment is… "ERROR: Coverage ... threshold"Fix Vitest "ERROR: Coverage for lines does not meet threshold" in CI - new untested code, an `all: true` conf… "Environment jsdom ... was not found"Fix Vitest "Cannot find package jsdom" / "environment happy-dom not found" in CI - the test environment packa… "Coverage ... does not meet ... threshold"Fix Vitest coverage threshold failures in CI - "ERROR: Coverage for lines does not meet global threshold" fai… "failed to access its internal state"Fix Vitest "Vitest failed to access its internal state" in CI - two copies of Vitest loaded at once, a versio… "failed to access its internal state"Fix Vitest "Vitest failed to access its internal state" in CI - caused by two copies of Vitest loaded at once… "Failed to load url ... vitest.config.ts"Fix Vitest "failed to load config from vitest.config.ts" in CI - the config file threw while loading, usually… "Failed to load ... setup file"Fix Vitest setupFiles errors in CI - a setup file path that does not resolve, or a setup that throws, aborts… "Failed to resolve import"Fix Vitest "Failed to resolve import 'X' from 'Y'. Does the file exist?" in CI - a missing dependency, an unc… "Failed to terminate worker"Fix Vitest "Failed to terminate worker" / "Terminating worker thread" in CI - a test left a timer, handle, or… "Cannot read properties of undefined (import.meta.env)"Fix Vitest "import.meta.env is undefined" in CI - env vars must be prefixed and available, or provided via te… "JavaScript heap out of memory"Fix Vitest "FATAL ERROR: Reached heap limit ... JavaScript heap out of memory" in CI - raise NODE_OPTIONS mem… "No test files found"Fix Vitest "No test files found, exiting with code 1" in CI - an include glob that matches nothing, the wrong… "No test files found, exiting with code 1"Fix Vitest "No test files found, exiting with code 1" in CI - the include glob matched nothing because of the… "No test files found"Fix Vitest "No test files found, exiting with code 1" in CI - an include glob that matches nothing, wrong wor… "Not implemented: HTMLCanvasElement.prototype.getContext"Fix Vitest "Not implemented: HTMLCanvasElement.prototype.getContext" in CI - jsdom/happy-dom do not implement… Vitest pool crashFix Vitest worker crashes and "Module did not self-register" / segfaults in CI by choosing the right pool - s… "ReferenceError: describe is not defined"Fix Vitest "ReferenceError: describe is not defined" / "expect is not defined" in CI - enable globals in conf… "Segmentation fault (core dumped)"Fix a "Segmentation fault" during Vitest in CI - a native addon or the worker pool crashed the Node process.… "Test timed out in 5000ms"Fix Vitest "Test timed out in 5000ms" in CI - a slow async test exceeded the default timeout. Raise testTimeo… "Test timed out in 5000ms"Fix Vitest "Test timed out in 5000ms" in CI - a test exceeded the default timeout, usually because an awaited… "does not provide an export named"Fix Vitest "The requested module does not provide an export named X" in CI - a named import does not exist on… "Transform failed with 1 error"Fix Vitest "Transform failed with 1 error" in CI - esbuild could not transform a file, usually a syntax error… "Unhandled Error" outside of testsFix Vitest "Unhandled Error" and unhandled rejections in CI - an error escaped a test (a leaked timer or prom… Vitest and Vite version mismatchFix Vitest and Vite version mismatch in CI - a Vitest peer expecting a different Vite major, or duplicate vit… "Vitest cannot be imported in a CommonJS module"Fix "Vitest cannot be imported in a CommonJS module using require()" in CI - Vitest is ESM-only. Load config… "vitest: command not found"Fix "vitest: command not found" in CI - the vitest binary is not installed or not on PATH because dependencie… "Failed to resolve import" (alias)Fix Vitest "Failed to resolve import @/..." in CI - path aliases from tsconfig are not applied unless configu… Browser mode provider missingFix Vitest browser mode failing in CI - a missing playwright/webdriverio provider, browsers not installed, or… "Executable doesn't exist" (browser mode)Fix Vitest browser mode failures in CI - the Playwright browser binary is not installed. Run playwright insta… Fake timers never advanceFix Vitest fake timer hangs in CI - after vi.useFakeTimers() you must advance time with vi.advanceTimersByTim… Worker terminated / pool crashFix Vitest "Terminating worker thread" / pool worker crashes in CI - a worker in the threads or forks pool di… Snapshot mismatch, update disabledFix Vitest snapshot mismatches in CI - Vitest refuses to write or update snapshots when CI=true. Update snaps… Vitest snapshot fails in CIFix Vitest snapshot failures in CI - in CI mode Vitest will not write or update snapshots, so a missing or st… "Unhandled Rejection"Fix Vitest runs failing on "Unhandled Rejection" / "This error originated in a hook" in CI - a promise reject… vi.mock "Cannot access before initialization"Fix Vitest "Cannot access X before initialization" from a vi.mock factory in CI - vi.mock is hoisted above im… Watch mode never exitsFix Vitest hanging in CI until timeout - bare `vitest` starts watch mode in a non-interactive terminal. Use `… "No projects matched the filter"Fix Vitest workspace errors in CI - "No projects matched the filter" or a bad workspace glob means the projec… Vitest workspace config errorFix Vitest workspace errors in a monorepo - duplicate workspace definitions, a glob matching no projects, or… "Cannot use import.meta"Fix "import.meta is not available" / "Cannot use import.meta outside a module" in tests - Jest CommonJS lacks…

E2E & browser

Cypress, Playwright, Selenium.

"No space left on device" (browsers)Fix "No space left on device" while installing browser binaries in CI - Chromium, Firefox, and WebKit downloa… "Chrome failed to start: crashed"Fix "unknown error: Chrome failed to start: crashed" in CI - Chrome exits at startup in a container, usually… small /dev/shm Chrome crashFix Chrome tab crashes in CI caused by a tiny /dev/shm - containers default to 64MB, which Chrome exhausts. A… "chromedriver ... not found in PATH"Fix "chromedriver executable needs to be in PATH" in CI - the WebDriver binary is not installed or not on PAT… "only supports Chrome version X"Fix "session not created: This version of ChromeDriver only supports Chrome version X" in CI - the ChromeDriv… "the Chromium Renderer process just crashed"Fix Cypress "We detected that the Chromium Renderer process just crashed" in CI - the container's tiny /dev/s… "Could not find a Cypress configuration file"Fix Cypress "Could not find a Cypress configuration file" in CI - running from the wrong directory, a missing… "could not verify ... server is running"Fix Cypress "Cypress could not verify that this server is running" in CI - the app under test was not started… "Cypress could not verify that this server is running"Fix Cypress "Cypress could not verify that this server is running" in CI - the baseUrl did not respond when C… "cy.visit() failed trying to load"Fix Cypress "cy.visit() failed trying to load ... We received this error: ECONNREFUSED" in CI - the app was n… "cy.visit() failed"Fix Cypress "cy.visit() failed trying to load" in CI - a non-2xx/3xx status, a connection refused, or a redir… "Cypress detected a cross origin error"Fix Cypress "Cypress detected a cross origin error happened on page load" in CI - the test navigated to a dif… "cross origin error"Fix Cypress "Cypress detected a cross origin error happened" in CI - a redirect to another superdomain (OAuth… Run-all-specs unavailableFix Cypress "Run all specs" missing or failing - experimentalRunAllSpecs not enabled, a version that dropped/… "Your system is missing the dependency: Xvfb"Fix Cypress "Your system is missing the dependency: Xvfb" / "Failed to connect to the X server" in CI - the h… "libgtk-3.so.0: cannot open shared object file"Fix Cypress "error while loading shared libraries: libgtk-3.so.0" in CI - the bundled Electron/Chrome browser… "out of memory or has crashed"Fix Cypress "The Test Runner unexpectedly exited... browser ran out of memory or has crashed" in CI - disable… "Record Key ... not valid"Fix Cypress Cloud "Your Record Key is not valid" / "You passed the --record flag but did not provide a Record… "the browser ... crashed"Fix Cypress "We detected that the Chromium Renderer process just crashed" in CI - a tiny container /dev/shm.… "The Cypress App could not be downloaded"Fix Cypress "The Cypress App could not be downloaded" in CI - the postinstall binary fetch was blocked, timed… "The Test Runner unexpectedly exited"Fix Cypress "The Test Runner unexpectedly exited via a exit event signal SIGSEGV/SIGKILL" in CI - the browser… "Timed out retrying after 4000ms"Fix Cypress "Timed out retrying after 4000ms: Expected to find element... but never found it" in CI - slow re… "Timed out retrying"Fix Cypress "Timed out retrying after 4000ms: Expected to find element" in CI - slow renders, a wrong selecto… "Timed out retrying after 4000ms"Fix Cypress "Timed out retrying after 4000ms: Expected to find element" in CI - the element or assertion neve… "verification timed out"Fix Cypress "Cypress verification timed out" and "Timed out waiting for the browser to connect" in CI - a slo… "Cypress verification timed out"Fix Cypress "Timed out waiting for the browser to connect. ... verification timed out" in CI - the smoke chec… "binary ... verification timed out"Fix Cypress "Timed out waiting for the browser to connect" / binary verification failures in CI - a corrupt c… "We failed processing this video"Fix Cypress "Warning: We failed processing this video" in CI - ffmpeg could not compress the run video, often… "Webpack Compilation Error"Fix Cypress "Webpack Compilation Error" in CI - a spec or support file that fails to bundle: a bad import, a… "You passed the --parallel flag but did not provide ... a Record Key"Fix Cypress "You passed the --parallel flag, but ... no Record Key" in CI - parallelization needs --record an… "Your configFile is invalid"Fix Cypress "Your configFile is invalid" / "must export a valid configuration" - a thrown require, ESM/CJS mi… "Your configFile is invalid"Fix Cypress "Your configFile is invalid" in CI - a syntax/require error in cypress.config.js, an unknown opti… "missing the dependency: Xvfb"Fix Cypress "Your system is missing the dependency: Xvfb" in CI - a headed or Electron run needs a virtual X… "ECONNREFUSED" baseUrlFix Cypress "could not verify that this server is running" / ECONNREFUSED on baseUrl in CI - the app was not… baseUrl differs from CYPRESS_BASE_URLFix Cypress tests hitting the wrong baseUrl in CI - the config baseUrl, the CYPRESS_BASE_URL env var, and the… "Cypress verification timed out"Fix Cypress "Cypress verification timed out" and "Cypress failed to start" in CI - the smoke test that runs t… "cy.mount is not a function"Fix Cypress component testing "cy.mount is not a function" - the mount command is not registered in the suppo… "dev-server: ... failed to start"Fix Cypress component testing "Cypress failed to start the dev server" - a wrong framework/bundler pairing, a… CYPRESS_CACHE_FOLDER mismatchFix Cypress re-downloading the binary every run in CI - CYPRESS_CACHE_FOLDER and the cache action point at di… CYPRESS_INSTALL_BINARY misconfiguredFix Cypress install failures from a misconfigured CYPRESS_INSTALL_BINARY in CI - the variable points at a mir… "geckodriver ... needs to be in PATH"Fix "geckodriver executable needs to be in PATH" in CI - the Firefox WebDriver binary is missing or off PATH,… "error while loading shared libraries"Fix headless-browser "error while loading shared libraries: libnss3.so" in a CI container - slim images lack… "have not captured in 60000 ms, killing"Fix Karma "Chrome have not captured in 60000 ms, killing" in CI - the browser launched but did not connect to… "There is no captured browser"Fix Karma "There is no captured browser, open http://localhost:9876/" in CI - no browser connected to the Kar… "Error retrieving a new session"Fix Nightwatch "Error retrieving a new session from the selenium server" / connection to 127.0.0.1:4444 refus… "element was not found" (timeout)Fix Nightwatch "TimeoutError: timed out while waiting for element ... to be present" in CI - a waitForElement… "--shard" wrong splitFix Playwright sharding mistakes in CI - a bad --shard=index/total, mismatched matrix totals, or merge-report… "Executable doesn't exist"Fix Playwright "browserType.launch: Executable doesn't exist" in CI - the browser binaries were never downloa… "browserType.launch: Failed to launch"Fix Playwright "browserType.launch: Failed to launch" in CI - the browser process started and exited immediat… "Download failed: server returned code 403"Fix Playwright "Download failed: server returned code 403" in CI - a proxy or firewall blocked the browser CD… "Download failed: size mismatch"Fix Playwright "Failed to download ... Download failed: size mismatch" in CI - the browser binary download wa… "Error in global setup"Fix Playwright globalSetup failures in CI - a thrown setup script, a failed auth/login step, or a saved stora… "libnss3.so: cannot open shared object file"Fix Playwright "error while loading shared libraries: libnss3.so: cannot open shared object file" in CI - the… "No tests found" (sharding)Fix Playwright "Error: No tests found" when running with --shard in CI - the shard index/total is misconfigur… "chromium_headless_shell ... Executable doesn't exist"Fix Playwright "Executable doesn't exist at .../chromium_headless_shell" in CI - the cached browser path has… "Executable doesn't exist at ..."Fix Playwright "Executable doesn't exist at ... run 'npx playwright install'" in CI - the browser binary was… "Executable doesn't exist"Fix Playwright "browserType.launch: Executable doesn't exist" in CI - the browser binaries were never downloa… "expect.poll ... exceeded"Fix Playwright "expect.poll() ... Timeout exceeded while waiting" in CI - a polled API/value that never reach… "expect(locator).toBeVisible() ... timeout"Fix Playwright "Timed out 5000ms waiting for expect(locator).toBeVisible()" in CI - slow render, an element h… "expect(page).toHaveURL" failedFix Playwright "expect(page).toHaveURL(expected)" failures in CI - the assertion ran while the page was still… "expect(locator).toHaveText" failedFix Playwright "expect(received).toHaveText(expected)" failures that pass locally but fail in CI - the assert… fullyParallel shared-state flakeFix Playwright flakiness introduced by fullyParallel in CI - tests that share a backend account, fixed data,… "Host system is missing dependencies"Fix Playwright "Host system is missing dependencies to run browsers" in CI - the browser binary downloaded bu… "Host system is missing dependencies"Fix Playwright "Host system is missing dependencies to run browsers" in CI - the browser binary downloaded bu… "missing dependencies to run browsers"Fix Playwright "Host system is missing dependencies to run browsers" in CI - shared libraries the browsers ne… "... is already used, make sure that nothing is running"Fix Playwright webServer "http://localhost:3000 is already used" in CI - a process is already bound to the po… "locator.waitFor: Timeout ... exceeded"Fix Playwright "locator.waitFor: Timeout 30000ms exceeded" in CI - the element never reached the expected sta… "net::ERR_CONNECTION_REFUSED"Fix Playwright "page.goto: net::ERR_CONNECTION_REFUSED" in CI - the test navigated before the app/webServer w… "No files were found" (trace/report)Fix the upload-artifact warning "No files were found with the provided path: playwright-report" in CI - the t… "net::ERR_CONNECTION_REFUSED"Fix Playwright "page.goto: net::ERR_CONNECTION_REFUSED at http://localhost:3000" in CI - the app under test w… "page.goto: Timeout 30000ms exceeded"Fix Playwright "page.goto: Timeout 30000ms exceeded" in CI - navigation never reached the configured load sta… "strict mode violation"Fix Playwright "strict mode violation: locator resolved to N elements" - narrow the locator with a role, exac… "Target ... has been closed"Fix Playwright "Target page, context or browser has been closed" in CI - using a page after teardown, a navig… "Target ... has been closed"Fix Playwright "Target page, context or browser has been closed" in CI - using a page after teardown, a brows… "Target page, context or browser has been closed"Fix Playwright "Target page, context or browser has been closed" in CI - an action ran against a page or cont… "Test timeout of 30000ms exceeded"Fix Playwright "Test timeout of 30000ms exceeded" / "locator ... Timeout exceeded" in CI - slow navigation, a… "Timeout 30000ms exceeded"Fix Playwright "Test timeout of 30000ms exceeded" / "locator ... Timeout exceeded" in CI - slow navigation, a… "config.webServer" timed outFix Playwright "Timed out waiting 60000ms from config.webServer" in CI - the app under test was slow to boot… "config.webServer" timed outFix Playwright "Timed out waiting 60000ms from config.webServer" in CI - the app was slow to boot or never be… webServer port conflictFix Playwright webServer failures from reuseExistingServer in CI - "port is already used" when reuse is false… Browser download fails (proxy)Fix Playwright "Failed to download" / browser install failures behind a corporate proxy or firewall - set HTT… Playwright download timeoutFix Playwright browser download timeouts in CI - the archive stalled or the connection dropped mid-transfer b… Flaky - passes on retryFix Playwright flaky tests that fail once then pass on retry in CI - races on async state, fixed sleeps, or s… Playwright "flaky" (passed on retry)Fix Playwright flaky tests marked "flaky" because they fail then pass on retry in CI - the run is green but t… PLAYWRIGHT_BROWSERS_PATH cache missFix Playwright browser cache misses in CI caused by PLAYWRIGHT_BROWSERS_PATH - the install and the test run p… Trace/report upload failsFix Playwright trace and HTML report artifacts not uploading in CI - traces only kept on retry, a wrong artif… playwright vs @playwright/test mismatchFix a Playwright / @playwright/test version mismatch in CI - the installed browser revision does not match th… Video/screenshot not savedFix Playwright videos and screenshots missing from CI artifacts - a capture mode that never records, outputDi… "Could not find Chromium (rev. X)"Fix Puppeteer "Could not find Chromium (rev. X)" and "Could not find expected browser" in CI - the bundled Ch… "Could not find Chromium"Fix Puppeteer "Could not find Chromium (rev. NNNNN)" in CI - a skipped download (PUPPETEER_SKIP_DOWNLOAD) or… "Could not find expected browser (chrome)"Fix Puppeteer "Could not find expected browser (chrome) locally" in CI - PUPPETEER_SKIP_DOWNLOAD or a cache m… "error while loading shared libraries: libX11.so"Fix Puppeteer / Chromium "error while loading shared libraries: libX11.so.6" in CI - the bundled Chrome links… "No usable sandbox!"Fix Puppeteer "Error: Failed to launch the browser process! ... No usable sandbox!" in CI - Chromium cannot e… "No usable sandbox!"Fix Puppeteer "Failed to launch the browser process ... No usable sandbox!" in CI - Chromium's sandbox cannot… "Failed to launch the browser process"Fix Puppeteer "Failed to launch the browser process" in CI - running Chrome as root needs --no-sandbox, plus… "Navigation timeout of 30000 ms exceeded"Fix Puppeteer "TimeoutError: Navigation timeout of 30000 ms exceeded" in CI - page.goto or waitForNavigation… "Protocol error ... Target closed"Fix Puppeteer "Protocol error (Runtime.callFunctionOn): Target closed" in CI - the browser or page crashed mi… PUPPETEER_CACHE_DIR mismatchFix Puppeteer browser-not-found errors caused by PUPPETEER_CACHE_DIR in CI - the install and the launch resol… PUPPETEER_SKIP_DOWNLOAD setFix Puppeteer failures when PUPPETEER_SKIP_DOWNLOAD or PUPPETEER_SKIP_CHROMIUM_DOWNLOAD is set in CI - the in… "'chromedriver' executable needs to be in PATH"Fix Selenium "WebDriverException: Message: 'chromedriver' executable needs to be in PATH" in CI - the driver… "element click intercepted"Fix Selenium "ElementClickInterceptedException: element click intercepted: Other element would receive the cl… "ElementClickInterceptedException"Fix Selenium "ElementClickInterceptedException: element click intercepted" - another element (overlay, sticky… "ElementNotInteractable"Fix Selenium "ElementNotInteractableException" and "element click intercepted" in CI - clicking an element th… "binary is not a Firefox executable"Fix Selenium "InvalidArgumentException: Message: binary is not a Firefox executable" / wrong binary path in C… "Unable to locate element"Fix Selenium "NoSuchElementException: Message: no such element: Unable to locate element" in CI - the element… "session not created"Fix Selenium "SessionNotCreatedException: this version of ChromeDriver only supports Chrome version N" in CI… "only supports Chrome version X"Fix Selenium "SessionNotCreatedException: ... This version of ChromeDriver only supports Chrome version X" in… "SessionNotCreatedException"Fix Selenium "SessionNotCreatedException: This version of ChromeDriver only supports Chrome version N" in CI… "StaleElementReferenceException"Fix Selenium "StaleElementReferenceException: element is not attached to the page document" - re-locate eleme… "TimeoutException" (WebDriverWait)Fix Selenium "TimeoutException: Message:" from WebDriverWait in CI - the expected condition never became true… "Connection refused"Fix Selenium "WebDriverException: ... Connection refused" / "Max retries exceeded" in CI - a remote Grid/Stan… "chrome not reachable"Fix Selenium "WebDriverException: unknown error: chrome not reachable" / "DevToolsActivePort file doesn't exi… "Chrome failed to start: crashed"Fix Selenium "unknown error: Chrome failed to start: crashed (chrome not reachable)" in CI - headless Chrome… "Could not start a new session"Fix Selenium Grid "Could not start a new session. Possible causes are invalid address of the remote server or… "Could not start a new session"Fix Selenium Grid "Could not start a new session" / "no node supports the capabilities" in CI - no matching n… "No nodes ... matching the requested capabilities"Fix Selenium Grid "Unable to find provider for session" / no node matching the requested capabilities in CI -… "Unable to obtain driver"Fix Selenium Manager "Unable to obtain driver for chrome using Selenium Manager" in CI - the automatic driver… "Unable to establish ... browser connection"Fix TestCafe "Unable to establish one or more of the specified browser connections" in CI - the launched brow… "unable to find the browser"Fix TestCafe "The specified ... browser is not found" / unable to resolve the browser in CI - the named brows… "Couldn't find the driver binary"Fix WebdriverIO "ERROR @wdio/cli: Couldn't find the driver binary" in CI - the local runner could not resolve… "ECONNREFUSED 127.0.0.1:4444"Fix WebdriverIO "ECONNREFUSED 127.0.0.1:4444" in CI - wdio tried to reach a WebDriver server on port 4444 tha… "session not created" (wdio)Fix WebdriverIO "session not created: This version of ChromeDriver only supports Chrome version X" in CI - th…

Other languages

RSpec, PHPUnit, and more.

"No test matches ... filter"Fix "dotnet test: No test matches the given testcase filter" / "No test is available" in CI - a too-narrow --… "Couldn’t find any files to test"Fix AVA "Couldn’t find any files to test" in CI - a files glob that matches nothing, default patterns missing… "unauthorized" (Centrifugo)Fix Centrifugo "unauthorized" disconnect in CI - the client connected without a valid JWT, so the server reje… "connection refused" (Centrifugo)Fix a Centrifugo client "connection refused" error in CI - the realtime client dialed the Centrifugo server b… Coverage upload failedFix coverage upload failures in CI - Codecov/Coveralls "failed to upload" or "rate limit / no token". A missi… "connect ECONNREFUSED" (Dredd)Fix Dredd "Error connecting to server ... ECONNREFUSED" in CI - Dredd ran against the API endpoint before the… "Assertion(s) failed !"Fix Gatling "Assertion(s) failed" in CI - a global assertion on response time percentiles or failure rate was… "j.n.ConnectException: Connection refused"Fix Gatling "j.n.ConnectException: Connection refused" in CI - the target host refused connections because th… "OutOfMemoryError: Java heap space"Fix Gatling "java.lang.OutOfMemoryError: Java heap space" in CI - a high user count or large response bufferi… "No simulations to run"Fix Gatling "There is no simulation script" or "No simulations to run" in CI - Gatling found no compiled simu… "Gatling simulation ... failed"Fix the Gatling Maven plugin reporting "Gatling simulation ... failed" in CI - the mvnw gatling:test goal fai… "WARNING: DATA RACE"Fix Go "WARNING: DATA RACE" from go test -race in CI - concurrent unsynchronized access to a shared variable,… go test "cannot find package"Fix "go test" "cannot find package" / "package X is not in std" build errors in CI - the test build cannot re… testify suite skippedFix testify suite methods never executing - no top-level Test function calling suite.Run, wrong method receiv… "Received RST_STREAM with code 2"Fix the gRPC error "Received RST_STREAM with code 2" in CI - the peer sent an HTTP/2 RST_STREAM frame to canc… "DEADLINE_EXCEEDED" (stream)Fix the gRPC streaming error "4 DEADLINE_EXCEEDED" in CI - the streaming RPC did not complete within its dead… "Stream removed"Fix the gRPC streaming error "13 INTERNAL: Stream removed" in CI - the HTTP/2 stream was torn down before the… "No specs found"Fix Jasmine "No specs found" in CI - a spec_dir/spec_files glob that matches nothing, wrong working directory… "OutOfMemoryError: Java heap space" (JMeter)Fix JMeter "java.lang.OutOfMemoryError: Java heap space" in CI - many threads or listeners saving full result… "jmeter: command not found"Fix "jmeter: command not found" in CI - JMeter is not installed on the runner or its bin directory is not on… "Non HTTP response code: java.net.ConnectException"Fix JMeter "Non HTTP response code: java.net.ConnectException" in CI - samplers could not connect to the targ… "Error in NonGUIDriver"Fix JMeter "An error occurred: Error in NonGUIDriver" in CI - the non-GUI run could not start because the tes… JUnit "No runnable methods"Fix JUnit "java.lang.Exception: No runnable methods" in CI - a test class has no @Test methods the runner rec… "No test report files were found"Fix CI "No test report files were found" matching a JUnit path - the reporter did not write the XML, or the p… "dial tcp: connect: connection refused"Fix k6 "GoError: Get ... dial tcp: connect: connection refused" in CI - the target service was not listening… "level=error ... Request Failed"Fix k6 "level=error msg=Request Failed" in CI - individual HTTP requests errored during the load test from ti… "some thresholds have failed"Fix k6 "some thresholds have failed" in CI - a per-check or tagged threshold did not meet its criterion, fail… "thresholds on metrics ... have been crossed"Fix k6 "some thresholds have failed" in CI - a checks or http_req_failed threshold was crossed because API re… "thresholds have been crossed"Fix k6 "some thresholds have been crossed" with exit code 99 in CI - a defined threshold failed, so k6 delibe… "signal: killed" / k6 OOMFix k6 running out of memory in CI - too many virtual users or a heavy per-VU script exhausted runner RAM and… "not found" feature pathFix Karate "feature not found" and "no features found" in CI - the classpath or file path to the .feature fil… "js failed ... ReferenceError"Fix Karate "js failed" with a "ReferenceError: ... is not defined" in CI - a JavaScript expression in a featu… "status code was: 500, expected: 200"Fix Karate "status code was: 500, expected: 200" in CI - a Status step matched a different HTTP status than t… "Cannot start Chrome"Fix Karma "Cannot start Chrome" / "No binary for Chrome browser" in CI - use ChromeHeadless with --no-sandbox… "No binary for ChromeHeadless"Fix Karma "No binary for ChromeHeadless browser on your platform" in CI - Chrome not installed, CHROME_BIN un… "Address already in use"Fix a load test failing with "Address already in use" in CI - the load generator or an embedded server could… "connection refused" (no wait-for-ready)Fix load tests failing early with connection refused in CI - the test started before the target service was r… Ramp too steep for the generatorFix a load test where an over-aggressive ramp saturates the load generator in CI, producing spurious failures… Results missing / gate cannot parseFix a load-test CI job where results are not saved or parsed - the run passes blindly because output was neve… Thresholds/assertions never gateFix misconfigured load-test thresholds in CI - a metric name typo or missing assertion means the gate never f… Wrong baseUrl / TLS handshake failureFix load tests hitting the wrong base URL or failing the TLS handshake in CI - requests go to the wrong host,… "locust: error: unrecognized arguments"Fix "locust: error: unrecognized arguments" in CI - a flag passed to Locust is misspelled, deprecated, or a c… "Failed to connect to master"Fix Locust workers logging "Failed to connect to master" in CI - a distributed worker could not reach the mas… "--exit-code-on-error" fails the jobFix a Locust CI job failing on --exit-code-on-error - Locust exited non-zero because requests failed and you… Locust "RPS 0" / 100% failuresFix Locust reporting 0 requests per second or 100% failures in CI - the host is unreachable, the base URL is… "ERR_REQUIRE_ESM" (--require)Fix Mocha "ERR_REQUIRE_ESM" when a --require setup file is ESM - switch to --import (Node 20+) or --loader, o… .mocharc not appliedFix Mocha ignoring .mocharc in CI - a config in the wrong location, an ESM/CJS rc mismatch, or CLI flags over… "Connection refused: Not authorized"Fix the MQTT client error "Connection refused: Not authorized" in CI - the broker rejected the CONNECT with a… "expected response to have status code 200"Fix Newman "AssertionError: expected response to have status code 200 but got 500" in CI - a Postman test ass… "connect ECONNREFUSED 127.0.0.1"Fix Newman "ECONNREFUSED" in CI - Newman ran against localhost before the API server had finished starting, s… "newman: command not found"Fix "newman: command not found" in CI - the Newman CLI is not installed on the runner or is not on PATH when… "unable to read data from file"Fix Newman "unable to read data from file" in CI - Newman cannot open the collection, environment, or data fi… NUnit parallel state conflictFix NUnit tests that fail only with [Parallelizable] in CI - fixtures sharing static state, a single database… "No coverage information"Fix nyc/c8 reporting 0% or "No coverage information was collected" in CI - a child process not instrumented,… "No pacts found"Fix Pact "No pacts found" in CI - provider verification found no contracts to verify because the consumer nam… "Verification failed"Fix Pact "Verification failed" in CI - the provider response did not match the consumer contract, so provider… "401 Unauthorized" publishing pactsFix Pact "could not be published" with a 401 from the Pact Broker in CI - the publish request reached the bro… "(exit) ... channel ... timeout"Fix Phoenix Channels channel join timeout in CI - a ChannelTest push/join did not receive a reply within the… "no connection to the server"Fix Phoenix Channels "unable to join, no connection to the server" in CI - the JS Socket never connected, so… "phx_error"Fix Phoenix Channels "phx_error" in CI - the channel crashed or the socket errored, so the client received a… "Could not read \"phpunit.xml\""Fix PHPUnit "Could not read phpunit.xml" / "Cannot open file" in CI - PHPUnit cannot find or parse the config… "Class ... not found"Fix PHPUnit "Error: Class ... not found" in CI - Composer autoload not regenerated, a PSR-4 namespace/path mi… PHPUnit "I" incomplete testsFix PHPUnit "There was 1 incomplete test" in CI - markTestIncomplete left tests unfinished, which can mask ga… "No code coverage driver is available"Fix PHPUnit "Error: No code coverage driver is available" in CI - coverage was requested but neither Xdebug n… "No tests executed!"Fix PHPUnit "No tests executed!" in CI - a testsuite directory that matches nothing, wrong suffix, or test cl… "risky test" / deprecations failFix PHPUnit failing CI on "risky" tests (no assertions, unexpected output) or deprecations promoted to failur… "did not perform any assertions"Fix PHPUnit risky tests - "This test did not perform any assertions" failing CI under beStrictAboutTestsThatD… "ERROR: file or directory not found"Fix pytest "ERROR: file or directory not found: X" in CI - a path passed to pytest does not exist on the runn… "errors during collection"Fix pytest "!!! Interrupted: N errors during collection" (exit code 2) in CI - a test module raised while pyt… "Unknown config option"Fix pytest "PytestConfigWarning: Unknown config option: X" or strict-config error in CI - a key in pytest.ini… pytest "filterwarnings = error"Fix pytest failures where a warning becomes an error in CI - with filterwarnings = error a DeprecationWarning… "not wrapped in act(...)"Fix React "An update to X inside a test was not wrapped in act(...)" - a state update after the test ended; a… "Expected status code <200> but was <500>"Fix REST Assured "Expected status code <200> but was <500>" in CI - the statusCode() expectation failed becau… "java.net.ConnectException: Connection refused"Fix REST Assured "java.net.ConnectException: Connection refused" in CI - the test fired a request before the… "JsonParseException: Unexpected character"Fix REST Assured "com.fasterxml.jackson.core.JsonParseException" in CI - REST Assured tried to parse a non-JS… "error ... before(:suite) hook"Fix RSpec "An error occurred in a before(:suite) hook" in CI - a failing global setup (DB connection, schema… "Failure/Error: ... ActiveRecord"Fix RSpec "Failure/Error" ActiveRecord errors in CI - PendingMigrationError, a missing test database, or sche… "cannot load such file"Fix RSpec "LoadError: cannot load such file -- rails_helper" / a gem in CI - a missing require path, an unins… "uninitialized constant"Fix RSpec "NameError: uninitialized constant X" in CI - a missing require, a Zeitwerk filename/class mismatch… DB state leaks between examplesFix RSpec examples polluting each other via leftover DB rows - configure database_cleaner transaction vs trun… RSpec order dependencyFix RSpec failures that only appear in random order in CI - leaked global state, unrolled-back data, or share… "server_error" (1 failed)Fix Schemathesis "1 failed" with a server_error check in CI - a generated request triggered a 500 from the AP… "Failed to load schema"Fix Schemathesis "Failed to load schema" in CI - Schemathesis could not fetch or parse the OpenAPI schema at… "Undocumented HTTP status code"Fix Schemathesis "Undocumented HTTP status code" in CI - the API returned a status the OpenAPI schema does no… "Cannot start a HubConnection ... Disconnected state"Fix SignalR "Cannot start a HubConnection that is not in the 'Disconnected' state" in CI - start() was called… "Failed to complete negotiation with the server"Fix SignalR "Failed to complete negotiation with the server" in CI - the initial HTTP negotiate request to th… "WebSocket closed with status code: 1006"Fix SignalR "Error: WebSocket closed with status code: 1006" in CI - the WebSocket closed abnormally with no… "assertion failed" (testrunner)Fix SoapUI testrunner assertion failures in CI - a test step assertion did not pass, so testrunner reports th… "connect_error ... websocket error"Fix Socket.IO "connect_error" with message "websocket error" in CI - the WebSocket transport upgrade failed b… "xhr poll error"Fix Socket.IO "Error: xhr poll error" in CI - the client's HTTP long-polling handshake could not reach the se… "Timeout" waiting for connectionFix Socket.IO "Error: Timeout" / connection timeout in CI tests - the client waited the full connect timeout… "EventSource ... connection error"Fix Server-Sent Events "EventSource connection error" in CI - the EventSource could not open or lost its stre… "net::ERR_INCOMPLETE_CHUNKED_ENCODING"Fix "net::ERR_INCOMPLETE_CHUNKED_ENCODING" on an SSE stream in CI - the chunked response ended without a prop… "Status code was ... expected ..."Fix Tavern "Status code was 500, expected 200" in CI - a Tavern stage response check failed because the API r… Sharding env misconfigFix test sharding env misconfig in CI - CI_NODE_INDEX/CI_NODE_TOTAL (or --shard) wrong, so shards overlap, sk… "Unable to find the browser"Fix TestCafe "Unable to find the browser" / "The specified browser is not found" in CI - a browser alias with… "Unable to find an element"Fix React Testing Library "Unable to find an element with the text/role" - use findBy for async UI, the right… "socket hang up"Fix the Node ws "Error: socket hang up" in CI - the TCP connection was closed before the WebSocket handshake… "Unexpected server response: 426"Fix the Node ws error "Unexpected server response: 426" (or 400) in CI - the server answered the WebSocket up… "WebSocket is not open: readyState 3 (CLOSED)"Fix the Node ws error "WebSocket is not open: readyState 3 (CLOSED)" in CI - a test called send() on a socket…
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GitHub ActionsWorkflow, runner, and YAML errors - diagnosed and fixed. Node.js & npmnpm, yarn, and pnpm failures in CI - solved. DockerBuild, run, compose, and registry errors - explained. Pythonpip, poetry, venv, and pytest failures - fixed. Java & JVMMaven, Gradle, and JVM failures in CI - resolved. GoGo build, module, and test failures - diagnosed.