SvelteKit deploy: the framework Worker packager resolves external packages with browser conditions, so @sentry/sveltekit fails to bundle #422

Problem

A SvelteKit + Void app imports @sentry/sveltekit (11.7.0) in src/hooks.server.ts. vp build passes. void deploy then fails at the packaging step, before anything is uploaded:

● sveltekit framework deploy
● Found 1 migration
◇ Bundling worker...
■ Build failed with 1 error:

  Error: [vite+]: Rolldown failed to resolve import "$app/stores" from
  "…/node_modules/@sentry/sveltekit/build/esm/client/svelte4BrowserTracing.js".
  This is most likely unintended because it can break your application at
  runtime.
  If you do want to externalize this module explicitly add it to
  `build.rolldownOptions.external`

The void deploy --platform cloudflare packager has the same problem and gives the same error.

pg/MySQL SvelteKit apps hit it too after #413, with the same error.

The same cause can also fail without any error at build time. postgres (3.4.9) packages fine, but the packager picks its Node build. Node's net/crypto/stream become an empty stub, so the first query fails in workerd:

• nodejs_als (the SvelteKit preset default): ReferenceError: Buffer is not defined
• nodejs_als + nodejs_compat: TypeError: import___vite_browser_external.default.Socket is not a constructor

Repro

Start from playground/sveltekit (D1 + KV, @sveltejs/adapter-cloudflare 8, Kit 3).

1. Add a dependency: "@sentry/sveltekit": "11.7.0".
2. Add src/hooks.server.ts:

   import * as Sentry from '@sentry/sveltekit';
   import { sequence } from '@sveltejs/kit/hooks';
   
   export const handle = sequence(
     Sentry.initCloudflareSentryHandle({ dsn: 'https://public@example.invalid/1', tracesSampleRate: 1 }),
     Sentry.sentryHandle(),
   );
   export const handleError = Sentry.handleErrorWithSentry();

3. Run:

   vp build                   # passes
   void deploy --skip-build   # fails at "Bundling worker..."

   For the native path, call prepareCfFrameworkBuildOutput (void deploy --platform cloudflare runs it as a preflight) on the same build. It fails with the same error.

Cause

Kit's server build leaves @sentry/sveltekit as a bare import (.svelte-kit/output/server/entries/hooks.server.js: import * as Sentry from "@sentry/sveltekit"). Void then bundles the adapter's _worker.js with a Vite lib build. That build has no ssr and no resolve.conditions, so Vite uses its client environment, with conditions ["module","browser","development|production"].

vp build (Kit + adapter-cloudflare)
  └─ .svelte-kit/cloudflare/_worker.js ──> hooks.server.js ──> "@sentry/sveltekit" (external)
            │
  void deploy                                void deploy --platform cloudflare
  runFrameworkDeploy                         prepareCfFrameworkBuildOutput
  bundleEntry  (wrapper.ts:520)              prepareBundledBuildOutput (cf-build-output.ts:205)
            └──── vite build({ build: { lib } }) → client env, "browser" condition ────┘
                                     │
   @sentry/sveltekit → build/esm/index.client.js → … → client/svelte4BrowserTracing.js
                                     └─ import "$app/stores"  ✗ (exists only inside Kit's build)

Code (on main, b58300f):

• packages/void/src/cli/preset.ts:115-124: the sveltekit preset sets bundle: true (:123). It is the only preset that does.
• packages/void/src/cli/deploy-managed-framework.ts:133-135: the hosted deploy calls bundleEntry(root, originalEntry).
• packages/void/src/cli/wrapper.ts:520-553: bundleEntry runs build({ root, build: { lib: { entry, formats: ['es'] }, … } }) and sets no conditions.
• packages/void/src/cli/deploy-cloudflare-build.ts:326-336: the native deploy runs prepareCfFrameworkBuildOutput for every worker-output preset (SvelteKit, Nuxt, Analog, Astro), as a preflight before remote changes. Only SvelteKit was tested.
• packages/void/src/cli/cf-build-output.ts:205-229: prepareBundledBuildOutput is the same kind of lib build (configFile: false, lib at :225).
• packages/void/src/plugin-framework.ts:280-321: for pg/MySQL, the void:sveltekit-worker-build plugin moves only void, drizzle-orm, the driver and packages that import void into Kit's workerd build. "Other dependencies stay external" (:287), so they still reach the browser-condition packager.

@sentry/sveltekit@11.7.0 package.json → exports["."]:

{
  "types": "./build/types/index.types.d.ts",
  "workerd": { "import": "./build/esm/index.workerd.js", "require": "./build/cjs/index.workerd.js" },
  "worker":  { "import": "./build/esm/index.worker.js",  "require": "./build/cjs/index.worker.js" },
  "browser": { "import": "./build/esm/index.client.js",  "require": "./build/cjs/index.client.js" },
  "node":    { "import": "./build/esm/index.server.js",  "require": "./build/cjs/index.server.js" },
  "default": { "import": "./build/esm/index.server.js",  "require": "./build/cjs/index.server.js" }
}

With the client conditions, only browser matches, so the import resolves to index.client.js. That file is browser code: it pulls in Kit's $app/* modules and does not export initCloudflareSentryHandle or sentryHandle.

postgres@3.4.9 exports["."] is { "workerd": "./cf/src/index.js", "import": "./src/index.js", … }. The client conditions skip workerd and match import, which is the Node build.

Check: the same bundleEntry options plus only resolve.conditions: ['workerd','worker','browser','module','import','default']:

• @sentry/sveltekit resolves to index.workerd.js. The build passes, and the Worker returns 200 for / in Miniflare with nodejs_als.
• postgres resolves to cf/src/index.js. The query reaches a real socket connect.

Suggested fix

Give both lib builds Worker resolve conditions. wrapper.ts:315-316 already defines WORKER_CONDITIONS and uses it for the SQL driver bundle (wrapper.ts:353-357). Use it in bundleEntry and prepareBundledBuildOutput (resolve: { conditions: WORKER_CONDITIONS }). prepareCfStaticBuildOutput (cf-build-output.ts:256) shares prepareBundledBuildOutput, so it gets the same change. Add a regression test with a fixture package that has both browser and workerd exports, and check that the packaged Worker uses the workerd file.

🤖 Generated with Claude Code

https://claude.ai/code/session_0123r5HnanmW2VUrZ7VWDufH