[Sveltekit] Strange behaviour of Source Maps

[hrueger]

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

7.54.0

Framework Version

@sveltejs/kit@1.20.1

Link to Sentry event

https://dein-ticket-shop.sentry.io/issues/4231736390/?project=4505312390610944&referrer=project-issue-stream

SDK Setup

Sentry.init({
    dsn: "[redacted]",
    tracesSampleRate: 1.0,
});

Steps to Reproduce

I just caught an error in my Sveltekit Project. However, the filepath is wrong:

However, source maps are uploaded and seem to be working partly?

Sentry was configured just as in the documentation, with the plugin in vite.config.js. No special settings / config, whatsoever.

Expected Result

I see the correct filename in sentry.

Actual Result

Wrong filename (see above)
I also can't connect GitHub, which is currently not possible due to the wrong filename:

(obviously there are no built files in my GitHub Repo).

Thanks for your help!

[lforst]

Hey, thanks for reporting this. Since the svelte-kit SDK (and the vite plugin) are still quite new we still have to figure out some stuff in regards to source maps.

The difficulty lies in svelte-kit seemingly having multiple build steps and keeping source maps and source files aligned throughout these build steps is a bit tricky. I believe we're in communication with Vercel and Rich Harris about this.

cc @Lms24

[hrueger]

Sure, no worries 👍 It's not super-important to me, as the build output is actually quite readable and not too different from the source (at least for the *.server.ts files)

[Lms24]

Hey @hrueger 👋 just a few questions:

• Which adapter are you using? Maybe we're incorrectly detecting the output path
• Are you using a custom out directory (i.e. not .svelte-kit)?

[hrueger]

Hi,
I'm using @sveltejs/adapter-node. No, no custom output directory. Here's my svelte.config.js:

import preprocess from 'svelte-preprocess';
import adapter from '@sveltejs/adapter-node';
import { vitePreprocess } from '@sveltejs/kit/vite';

const checkOrigin = process.env.NODE_ENV !== "development";

/** @type {import('@sveltejs/kit').Config} */
const config = {
	// Consult https://kit.svelte.dev/docs/integrations#preprocessors
	// for more information about preprocessors
	preprocess: [
		vitePreprocess(),
		preprocess({
			scss: {
				prependData: '@use "src/variables.scss" as *;'
			}
		})
	],

	kit: {
		adapter: adapter(),
		alias: {
			$myLib: '../_lib',
		},
		csrf: {
			checkOrigin
		}
	}
};

export default config;

So just the standard stuff, basically. I don't think it has something todo with the alias, since although prisma is declared inside the ../_lib folder, the file where the exception is thrown is not.

FYI I'm using a monorepo with multiple packages, but when I'm building, I'm doing that from inside the folder of the respective package, so that shouldn't be a problem either.