Sentry doesn't work with Wrangler Pages + Sveltekit

[ZombieChibiXD]

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/sveltekit

SDK Version

^10.31.0

Framework Version

"@sentry/sveltekit": "^10.31.0",

Link to Sentry event

No response

Reproduction Example/SDK Setup

//Hooks.server.ts
import { sequence } from '@sveltejs/kit/hooks';
import { handleErrorWithSentry, sentryHandle, initCloudflareSentryHandle } from '@sentry/sveltekit';
import * as Sentry from '@sentry/sveltekit';
import type { Handle } from '@sveltejs/kit';

export const handle = sequence(
	initCloudflareSentryHandle({
		dsn: 'https://bb5d40cdfe67937feac4980d449d83b5@o4510548762755072.ingest.us.sentry.io/4510548807122944',
		// Adds request headers and IP for users, for more info visit:
		// https://docs.sentry.io/platforms/javascript/guides/sveltekit/configuration/options/#sendDefaultPii
		sendDefaultPii: true
	}),
	sentryHandle(),
	({ event, resolve }) => {
		return resolve(event, {
			transformPageChunk: ({ html }) => html.replace('%lang%', event.locals.locale ?? 'en')
		});
	}
);

export const handleError = Sentry.handleErrorWithSentry();


//Hooks.client.ts
import { handleErrorWithSentry, replayIntegration } from "@sentry/sveltekit";
import * as Sentry from '@sentry/sveltekit';

Sentry.init({
  dsn: 'https://bb5d40cdfe67937feac4980d449d83b5@o4510548762755072.ingest.us.sentry.io/4510548807122944',

  tracesSampleRate: 1.0,

  // Enable logs to be sent to Sentry
  enableLogs: true,

  // This sets the sample rate to be 10%. You may want this to be 100% while
  // in development and sample at a lower rate in production
  replaysSessionSampleRate: 0.1,

  // If the entire session is not sampled, use the below sample rate to sample
  // sessions when an error occurs.
  replaysOnErrorSampleRate: 1.0,

  // If you don't want to use Session Replay, just remove the line below:
  integrations: [replayIntegration()],

  // Enable sending user PII (Personally Identifiable Information)
  // https://docs.sentry.io/platforms/javascript/guides/sveltekit/configuration/options/#sendDefaultPii
  sendDefaultPii: true,
});

// If you have a custom error handler, pass it to `handleErrorWithSentry`
export const handleError = handleErrorWithSentry();
// Instrumentation.server.ts
import * as Sentry from '@sentry/sveltekit';

Sentry.init({
  dsn: 'https://bb5d40cdfe67937feac4980d449d83b5@o4510548762755072.ingest.us.sentry.io/4510548807122944',

  tracesSampleRate: 1.0,

  // Enable logs to be sent to Sentry
  enableLogs: true,

  // uncomment the line below to enable Spotlight (https://spotlightjs.com)
  // spotlight: import.meta.env.DEV,
});

Steps to Reproduce

Attempt npm run build
Attempt npm wrangler pages dev
Failed because of

npx wrangler pages dev

 ⛅️ wrangler 4.50.0 (update available 4.55.0)
─────────────────────────────────────────────
X [ERROR] Build failed with 1 error:

  X [ERROR] Could not resolve
  "./..outputserverinstrumentation.server.js"

      _worker.js:1:7:
        1 │ import './..\output\server\instrumentation.server.js';
          ╵        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Expected Result

It should deploy the website so I can deploy on cloudflare pages

Actual Result

npx wrangler pages dev

 ⛅️ wrangler 4.50.0 (update available 4.55.0)
─────────────────────────────────────────────
X [ERROR] Build failed with 1 error:

  X [ERROR] Could not resolve
  "./..outputserverinstrumentation.server.js"

      _worker.js:1:7:
        1 │ import './..\output\server\instrumentation.server.js';
          ╵        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Additional Context

No response

Priority

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[linear]

JS-1324

[ZombieChibiXD]

for some reason

//_worker.js

import './..\output\server\instrumentation.server.js';
const { default: _0 } = await import('./start.js');
export { _0 as default };

have an inconsistent issue, if I change it, it'll work before a completely new error occurs

 ⛅️ wrangler 4.50.0 (update available 4.55.0)
─────────────────────────────────────────────
▲ [WARNING] Import "init" will always be undefined because there is no matching export in "../../node_modules/@sentry/sveltekit/build/esm/index.worker.js" [import-is-undefined]

    ../output/server/instrumentation.server.js:21:7:
      21 │ Sentry.init({
         ╵        ~~~~
...
⎔ Starting local server...
X [ERROR] service core:user:testweb: Uncaught TypeError: (void 0) is not a function

    at null.<anonymous> (5ckmgbumq0g.js:126910:9)



X [ERROR] The Workers runtime failed to start. There is likely additional logging output above.


If you think this is a bug then please create an issue at https://github.com/cloudflare/workers-sdk/issues/new/choose

[s1gr1d]

Hi and thanks for reaching out!

Which OS are you using? Is it Windows? Because the slashes are in different directions: ./..\output\server\instrumentation.server.js

I'm not sure if this is the culprit here but maybe you can try manually changing them to / to see if that would work.

[Lms24]

Please try deleting instrumentation.server.ts. Unfortunately, it doesn't seem to work on Cloudflare. Our docs recommend you initialize the SDK in the initCloudflareSentryHandle handler instead (which you're already doing).

(If this fixes it, we should make this more clear in our docs because I fully understand how this can be misunderstood at the moment)