LHError: Failed with error: PROTOCOL_TIMEOUT

Describe the bug

Lighthouse is timing out when trying to audit the page.

4:26:25 PM: ┌──────────────────────────────────────────────────────┐
4:26:25 PM: │ 2. onSuccess command from @netlify/plugin-lighthouse │
4:26:25 PM: └──────────────────────────────────────────────────────┘
4:26:25 PM: ​
4:26:25 PM: Serving and scanning site from directory out
4:26:25 PM: Tue, 30 Jun 2020 15:26:25 GMT ChromeLauncher Waiting for browser.
4:26:25 PM: Tue, 30 Jun 2020 15:26:25 GMT ChromeLauncher Waiting for browser...
4:26:26 PM: Tue, 30 Jun 2020 15:26:26 GMT ChromeLauncher Waiting for browser.....
4:26:26 PM: Tue, 30 Jun 2020 15:26:26 GMT ChromeLauncher Waiting for browser.....✓
4:26:26 PM: Tue, 30 Jun 2020 15:26:26 GMT config:warn IFrameElements gatherer requested, however no audit requires it.
4:26:26 PM: Tue, 30 Jun 2020 15:26:26 GMT config:warn InspectorIssues gatherer requested, however no audit requires it.
4:26:26 PM: Tue, 30 Jun 2020 15:26:26 GMT status Connecting to browser
4:26:26 PM: Tue, 30 Jun 2020 15:26:26 GMT status Resetting state with about:blank
4:26:26 PM: Tue, 30 Jun 2020 15:26:26 GMT status Benchmarking machine
4:26:27 PM: Tue, 30 Jun 2020 15:26:27 GMT status Initializing…
4:26:27 PM: Tue, 30 Jun 2020 15:26:27 GMT status Running defaultPass pass CSSUsage, JsUsage, ViewportDimensions, RuntimeExceptions, ConsoleMessages, AnchorElements, ImageElements, LinkElements, MetaElements, ScriptElements, IFrameElements, MainDocumentContent, AppCacheManifest, Doctype, DOMStats, OptimizedImages, PasswordInputsWithPreventedPaste, ResponseCompression, TagsBlockingFirstPaint, FontSize, EmbeddedContent, RobotsTxt, TapTargets, Accessibility, TraceElements, InspectorIssues, SourceMaps
4:26:27 PM: Tue, 30 Jun 2020 15:26:27 GMT status Resetting state with about:blank
4:26:27 PM: Tue, 30 Jun 2020 15:26:27 GMT status Setting up network for the pass trace
4:26:27 PM: Tue, 30 Jun 2020 15:26:27 GMT status Cleaning browser cache
4:26:27 PM: Tue, 30 Jun 2020 15:26:27 GMT status Beginning devtoolsLog and trace
4:26:27 PM: Tue, 30 Jun 2020 15:26:27 GMT status Loading page & waiting for onload
4:26:27 PM:  ⚠  warning (DeprecationWarning)  OutgoingMessage.prototype._headers is deprecated
4:26:27 PM: [DEP0066] 
4:26:27 PM:     at new module.exports (/opt/build/repo/node_modules/union/lib/response-stream.js:50:60)
4:26:27 PM:     at new module.exports (/opt/build/repo/node_modules/union/lib/routing-stream.js:30:17)
4:26:27 PM:     at Server.requestHandler (/opt/build/repo/node_modules/union/lib/core.js:27:25)
4:26:27 PM:     at Server.emit (events.js:315:20)
4:26:27 PM:     at parserOnIncoming (_http_server.js:790:12)
4:26:27 PM:     at HTTPParser.parserOnHeadersComplete (_http_common.js:119:17)
4:27:12 PM: Tue, 30 Jun 2020 15:27:12 GMT Driver:warn Timed out waiting for page load. Checking if page is hung...
4:27:13 PM: Tue, 30 Jun 2020 15:27:13 GMT Driver:warn Page appears to be hung, killing JavaScript...
4:27:43 PM: Tue, 30 Jun 2020 15:27:43 GMT status Disconnecting from browser...
4:27:43 PM: Tue, 30 Jun 2020 15:27:43 GMT ChromeLauncher Killing Chrome instance 1690
4:27:43 PM: Error: PROTOCOL_TIMEOUT
4:27:43 PM: ​
4:27:43 PM: ┌────────────────────────────────────────────┐
4:27:43 PM: │ Plugin "@netlify/plugin-lighthouse" failed │
4:27:43 PM: └────────────────────────────────────────────┘
4:27:43 PM: ​
4:27:43 PM:   Error message
4:27:43 PM:   LHError: Failed with error: PROTOCOL_TIMEOUT
4:27:43 PM:   PROTOCOL_TIMEOUT
4:27:43 PM: ​
4:27:43 PM:   Plugin details
4:27:43 PM:   Package:        @netlify/plugin-lighthouse
4:27:43 PM:   Version:        1.2.1
4:27:43 PM:   Repository:     git+https://github.com/netlify-labs/netlify-plugin-lighthouse.git
4:27:43 PM:   npm link:       https://www.npmjs.com/package/@netlify/plugin-lighthouse
4:27:43 PM:   Report issues:  https://github.com/netlify-labs/netlify-plugin-lighthouse/issues
4:27:43 PM: ​
4:27:43 PM:   Error location
4:27:43 PM:   In "onSuccess" event in "@netlify/plugin-lighthouse" from netlify.toml and package.json
4:27:43 PM:       at Timeout._onTimeout (/opt/build/repo/node_modules/lighthouse/lighthouse-core/gather/driver.js:352:21)
4:27:43 PM: ​
4:27:43 PM:   Resolved config
4:27:43 PM:   build:
4:27:43 PM:     base: /opt/build/repo/app1
4:27:43 PM:     command: yarn build
4:27:43 PM:     environment:
4:27:43 PM:       - REVIEW_ID
4:27:43 PM:     ignore: git diff --quiet HEAD^ HEAD ../app1/
4:27:43 PM:     publish: /opt/build/repo/app1/out
4:27:43 PM:   plugins:
4:27:43 PM:     - inputs: {}
4:27:43 PM:       origin: config
4:27:43 PM:       package: '@netlify/plugin-lighthouse'

To Reproduce

The repository is set up in the following manor:

package.json <- with @netlify/plugin-lighthouse dev dependency app1/netlify.toml app1/out <- this is where the static files are outputted to. app1/.... <- basic Next.js files & structure

app1/netlify.toml contains the following:

[build]
  command = "yarn build"
  publish = "out"
  ignore = "git diff --quiet HEAD^ HEAD ../app1/"

[[plugins]]
package = "@netlify/plugin-lighthouse"
  [plugins.inputs.thresholds]
    performance = 0.9
    accessibility = 0.9
    best-practices = 0.9

Additional context

• Deploying from a monorepo structure where the toml file is in the sub directory where the app source is and the base directory is set.
• Using Next.js to build and export the app into static files to be served.
• Running the plugin locally using the out directory worked fine. The issue just occurs when running on Netlify.

[alexjfno1]

I haven’t seen the issue first hand but if it’s the lighthouse library reporting null it sounds to me like it’s an issue for them.

Thanks for the fix, I’ll give it a go tomorrow at some point.

[alexjfno1]

Sure @erezrokah, I’ll raise a PR shortly.