@sentry/sveltekit import causing error with upgrade to 9.29.0

[RikuVan]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which SDK are you using?

@sentry/browser

SDK Version

9.29.0

Framework Version

sveltekit 2.21.1

Link to Sentry event

https://danceup-academy.sentry.io/issues/46616164/?alert_rule_id=183785&alert_timestamp=1749978555497&alert_type=email&environment=production&notification_uuid=d02d3778-4423-4f55-bd30-4154d0d3c61d&project=4509219253256272&referrer=alert_email

Reproduction Example/SDK Setup

import * as Sentry from '@sentry/sveltekit'
import type { Handle } from '@sveltejs/kit'
import { sequence } from '@sveltejs/kit/hooks'
import { paraglideMiddleware } from '$lib/paraglide/server'
import { getAccessToken } from '$lib/auth/getAccessToken'
import { env } from '$env/dynamic/private'
import { isRegistrationComplete } from '$lib/validation/isRegistrationComplete'

Sentry.init({
	dsn: 'https://foobar',
	tracesSampleRate: 1
})

const handleParaglide: Handle = ({ event, resolve }) =>
	paraglideMiddleware(event.request, ({ request, locale }) => {
		event.request = request

		return resolve(event, {
			transformPageChunk: ({ html }) => html.replace('%lang%', locale)
		})
	})

const handleSession: Handle = async ({ event, resolve }) => {
	const accessToken = await getAccessToken(event.cookies)

	if (!accessToken) {
		event.locals.user = null
		return resolve(event)
	}

	if (accessToken && !event.locals.user) {
		const res = await fetch(`${env.ROOT_API}/auth/me`, {
			headers: {
				Authorization: `Bearer ${accessToken}`
			}
		})

		if (res.ok) {
			const user = await res.json()
			event.locals.user = {
				...user,
				registrationIsComplete: isRegistrationComplete(user)
			}
		} else {
			console.error('Error fetching user in hooks.server.ts', res)
		}
	}

	event.locals.getAccessToken = getAccessToken

	return resolve(event)
}

export const handle: Handle = sequence(Sentry.sentryHandle(), handleSession, handleParaglide)

export const handleError = Sentry.handleErrorWithSentry()

Steps to Reproduce

1. upgrade to ^9.29.0
2. add code below to server.hooks.ts as seen in example
3. get error causing app to crash in production

Expected Result

App renders without 500 error on backend

Actual Result

2025-06-15 11:36:27.285 | This file is being treated as an ES module because it has a '.js' file extension and '/app/package.json' contains "type": "module". To treat it as a CommonJS script, rename it to use the '.cjs' file extension. |  

[andreiborza]

Hi @RikuVan, thanks for writing in.

I tried reproducing this with paraglide and our 9.29.0 SDK but didn't run into issues. I did mock out getAccessToken but to be honest, I'm not super familiar with SvelteKit so this might be just something on my side.

Could you please provide a reproduction repo?

[rbozan]

Hi @RikuVan, thanks for writing in.

I tried reproducing this with paraglide and our 9.29.0 SDK but didn't run into issues. I did mock out getAccessToken but to be honest, I'm not super familiar with SvelteKit so this might be just something on my side.

Could you please provide a reproduction repo?

For me this only happens on a production build. Running the build using node build does cause this issue for me when opening a route (but not all of them).

It's probably related to these issues:
sveltejs/kit#13869
#16507

Personally I reverted back to

svelte@5.33.14
@sveltejs/kit@2.21.2
@sentry/sveltekit@9.27.0