[WARNING] The package "node:async_hooks" wasn't found on the file system but is built into node.

[frederichoule]

Describe the bug

After upgrading:

• sveltekit: 2.19.1 to 2.20.3
• svelte: 5.23.0 to 5.25.6

Cloudflare now complains that "node:async_hooks" is being imported by _worker.js. This notice wasn't there on previous builds/previous versions.

Reproduction

You can create by creating a new Sveltekit project (using npx sv create) and deploying as Cloudflare pages.

Logs

System Info

N/A

Severity

annoyance

Additional Information

No response

[frederichoule]

Seems to be caused by #13582

[Conduitry]

If you're not using getRequestEvent(), then you don't need to worry about this. If you are using it, then you should set the nodejs_compat flag, as mentioned in the warning.

@eltigerchino I think you were mentioning some way we could deal with this by having the adapter influence the configuration of the deployment? https://developers.cloudflare.com/workers/wrangler/configuration/#generated-wrangler-configuration

[frederichoule]

I'm not using getRequestEvent(), so it doesn't affect me (and I don't want/have the nodejs_compat flag).

But I still like to have clean logs without warnings :-)

[eltigerchino]

@eltigerchino I think you were mentioning some way we could deal with this by having the adapter influence the configuration of the deployment? developers.cloudflare.com/workers/wrangler/configuration#generated-wrangler-configuration

Yes, that was the initial idea but it seems that generating a wrangler configuration is prone to getting out of sync with the user config if they don't re-run the build. Instead, the Cloudflare folks suggested adding an error message if the appropriate flags aren't set. Otherwise, we need to look at trying to treeshake this import away if the getRequestEvent() function isn't used.

I'd highly recommend enabling the nodejs_als compatibility flag in the meantime if you want to get rid of the warning. This doesn't seem to bundle any extra code in the worker from my testing compared to enabling the nodejs_compat flag which does.