Error Message: Attempted to get a SyntheticEventsManager without initializing

[patrick-mcdougle]

FAQ

• Yes, my issue is not about variability or throttling.
• Yes, my issue is not about a specific accessibility audit (file with axe-core instead).
• Yes, my issue is not answered by other FAQs.

URL

https://rothys.com/products/womens-almond-slingback-lollipop-red

What happened?

Many of the diagnostics show an error saying: "Required TraceElements gatherer encountered an error: Attempted to get a SyntheticEventsManager without initializing".

I don't know what this error message means, but I assume it has to do with some internals of lighthouse. If not, I would love to know what is being loaded on my site that is blocking this or causing this error.

What did you expect?

I expected to get diagnostic insights and not internal errors.

What have you tried?

I've tried to disable other RUM tools from being loaded just in case they were interfering with Lighthouse.

How were you running Lighthouse?

Chrome DevTools

Lighthouse Version

12.7.0

Chrome Version

140 (Canary)

Node Version

No response

OS

Mac

Relevant log output

[paulirish]

This is triggered because

Helpers.SyntheticEvents.SyntheticEventsManager.getActiveManager().registerSyntheticEvent is called directly in extractConsoleAPIExtensionEntries and extractPerformanceAPIExtensionEntries whereas this method SHOULD be called via the registerSyntheticEvent static method that does a try/catch to avoid this.

The good news is all other calls use the safe static method.

And that means this problem only happens on sites that are using the new e11y API https://developer.chrome.com/docs/devtools/performance/extension.

(Thanks @patrick-mcdougle for using the latest and greatest! very cool)

but also sad cuz.. in this case it basically bit you as our test coverage didnt cover this case.

[paulirish]

Trace that repros this problem: https://trace.cafe/t/Oij5oX5b3O when run directly through trace engine in LH.

[paulirish]

Chromium side fix : RPP: Prevent syntheticEvent registration from throwing (6701907) · Gerrit Code Review

[patrick-mcdougle]

Appreciate the swift work on this, didn't realize we were on the cutting edge!

A few questions (mostly to bubble up to my boss):

1. When can we expect this to be released in Canary?
2. When can we expect this to be released in page speed insights?
3. Is there a chance that this fix will result in a change in our lighthouse score?
4. Is there a chance that this would have effected our SEO rankings?

[connorjclark]

1. it's in canary now
2. likely early next week
3. no
4. no