Error: Could not load stylesheet (timeout)

[wardpeet]

I was checking sentry I saw that we got hit by this error quite a bit. About 12000 a day.

The issue is still CORS. We should throw Could not load stylesheet with CORS but we throw Could not load stylesheet (timeout). We should add an addEventListener('error' to the mix to track these errors correctly.

The above issue fixes logging the correct message but it won't fix these errors. The issue lies that we call the stylesheet with crossorigin="anonymous" and that chrome expects a 'Access-Control-Allow-Origin': '<value>' header which a lot of sites do not set as it's unnecessary.

Some options:

1. we read the raw data of the network record and do a regex on the raw text of the file. More error prone than cssStylesheet where parsing is already done
2. Override ACAO header with requestIntercepted unsure if this works.

https://sentry.io/google-lighthouse/lighthouse/issues/596333623/

Error: Could not load stylesheet (timeout)
  File "/usr/lib/node_modules/lighthouse/lighthouse-core/gather/gatherers/fonts.js", line 218, in fontsAndErrors.filter.fontOrError
    const err = new Error(dataError.err.message);
  ?, in Array.filter
  File "/usr/lib/node_modules/lighthouse/lighthouse-core/gather/gatherers/fonts.js", line 213, in fontData.then
    const fontFaces = /** @type {Array<LH.Artifacts.Font>} */ (fontsAndErrors.filter(
  ?, in null.<anonymous>
  File "internal/process/next_tick.js", line 182, in process._tickCallback

Error: Could not load stylesheet (timeout)

[wardpeet]

@paulirish @brendankenny how do you feel about these 2 options?

[exterkamp]

Was this fixed as part of #6166?

[patrickhulce]

Yep should've been fixed by #6166