[@sentry/sveltekit] `ReferenceError: Cannot access 'default' before initialization.` when version uses execSync or equivalent sync call

[hloth]

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?

Self-hosted/on-premise

Which SDK are you using?

@sentry/sveltekit

SDK Version

^10

Framework Version

sveltejs/kit@^2.37.0 + svelte@^5.38.6

Link to Sentry event

No response

Reproduction Example/SDK Setup

svelte.config.js:

import { execSync } from 'node:child_process'
import adapter from '@sveltejs/adapter-node'
import { vitePreprocess } from '@sveltejs/vite-plugin-svelte'

const config = {
  preprocess: vitePreprocess(),
  kit: {
    adapter: adapter(),

    version: {
      name:
        execSync('git rev-parse HEAD').toString().trimEnd().substring(0, 7) +
        '/' +
        process.env.PUBLIC_APP_ENV
    },

    experimental: {
      tracing: {
        server: true
      },

      instrumentation: {
        server: true
      }
    }
  }
}

export default config

Steps to Reproduce

1. Create svelte kit project
2. Put svelte.config.js above
3. Run project

Without version, with async version getting or without sentry source map plugin it works fine.

See https://svelte.dev/docs/kit/configuration#version

Expected Result

Version loads and source map plugin works

Actual Result

[Source Maps Plugin] Couldn't load svelte.config.js:
16 |   try {
17 |     if (!fs.existsSync(configFile)) {
18 |       return {};
19 |     }
20 |     // @ts-expect-error - we explicitly want to import the svelte config here.
21 |     const svelteConfigModule = await import(`${url.pathToFileURL(configFile).href}`);
                                                                                  ^
ReferenceError: Cannot access 'default' before initialization.
      at loadSvelteConfig (/path/to/node_modules/@sentry/sveltekit/build/esm/vite/svelteConfig.js:21:78)
      at spawnSync (node:child_process:226:22)
      at execSync (node:child_process:275:109)
      at /path/to/svelte.config.js:12:9
      at requestImportModule (2:1)

[linear]

JS-896 [@sentry/sveltekit] `ReferenceError: Cannot access 'default' before initialization.` when version uses execSync or equivalent sync call

[VityaSchel]

Workaround:

import adapter from '@sveltejs/adapter-node'
import { vitePreprocess } from '@sveltejs/vite-plugin-svelte'
import { execSync } from 'child_process'

let commit = 'unknown'

const config = {
  preprocess: vitePreprocess(),
  kit: {
    adapter: adapter(),

    version: {
      name: commit + '/' + process.env.PUBLIC_APP_ENV
    },

    experimental: {
      tracing: {
        server: true
      },

      instrumentation: {
        server: true
      }
    }
  }
}

export default config

commit = execSync('git rev-parse HEAD').toString().trimEnd().substring(0, 7)

config.kit.version.name = commit + '/' + process.env.PUBLIC_APP_ENV

[Lms24]

Hey @VityaSchel thanks for writing in! Not sure what changed because we didn't change the way how we load the svelte config but rather just the timing when we do it (a bit earlier now, when we initialize our vite plugins). I'm gonna try to reproduce and get back to you.

[Lms24]

@VityaSchel I couldn't yet reproduce this with a minimal sveltekit app. Can you take a look at https://github.com/Lms24/gh-sentry-javascript-17510-sveltekit-load-svelte-config-crash and let me know what to change so that this becomes reproducible? Alternatively, feel free to share your own reproduction app.

Thanks!

[Lms24]

Huh your other issue (#17511) gave away the important addition that's necessary to reproduce this. You have to run the build command with bun --bun run build. Specifically --bun seems to be necessary. I'm not sure actually if this is a Sentry bug then or rather a problem with bun. I'll investigate some more