`@sveltejs/adapter-auto` not detecting Cloudflare Workers
Open
A pull request for this has already been merged.
pkg:adapter-auto
pkg:adapter-cloudflare
- Dominant language
- JavaScript
- Stars
- 20.8k
- Forks
- 2.3k
- Avg merge
- 1d 16h
- Merged PRs (30d)
- 156
Description
Describe the bug
In Cloudflare Workers, this combination:
.node-versionfile- no lockfile
Results in Node.js and bun install
Detected the following tools from environment: nodejs@24.12.0, bun@1.2.15
Installing nodejs 24.12.0
Installing project dependencies: bun install
Which fails to detect the production environment:
Using @sveltejs/adapter-auto
Could not detect a supported production environment. See https://svelte.dev/docs/kit/adapters to learn how to configure your app to run on the platform of your choosing
Reproduction
https://github.com/hyunbinseo/svelte-kit-template/tree/cloudflare-workers
Logs
2025-12-14T15:16:11.196Z Initializing build environment...
2025-12-14T15:16:12.556Z Success: Finished initializing build environment
2025-12-14T15:16:12.953Z Cloning repository...
2025-12-14T15:16:13.931Z No build output detected to cache. Skipping.
2025-12-14T15:16:13.931Z No dependencies detected to cache. Skipping.
2025-12-14T15:16:20.389Z Detected the following tools from environment: nodejs@24.12.0, bun@1.2.15
2025-12-14T15:16:20.390Z Installing nodejs 24.12.0
2025-12-14T15:16:11.196Z Initializing build environment...
2025-12-14T15:16:12.556Z Success: Finished initializing build environment
2025-12-14T15:16:12.953Z Cloning repository...
2025-12-14T15:16:13.931Z No build output detected to cache. Skipping.
2025-12-14T15:16:13.931Z No dependencies detected to cache. Skipping.
2025-12-14T15:16:20.389Z Detected the following tools from environment: nodejs@24.12.0, bun@1.2.15
2025-12-14T15:16:20.390Z Installing nodejs 24.12.0
2025-12-14T15:16:25.238Z Installing project dependencies: bun install
2025-12-14T15:16:26.548Z [3.55ms] ".env"
2025-12-14T15:16:26.557Z bun install v1.2.15 (df017990)
2025-12-14T15:16:26.586Z Resolving dependencies
2025-12-14T15:16:35.263Z Resolved, downloaded and extracted [1100]
2025-12-14T15:16:36.469Z Saved lockfile
2025-12-14T15:16:36.470Z
2025-12-14T15:16:36.470Z $ svelte-kit sync || echo ''
2025-12-14T15:16:37.511Z
2025-12-14T15:16:37.513Z + @eslint/compat@2.0.0
2025-12-14T15:16:37.514Z + @eslint/js@9.39.2
2025-12-14T15:16:37.514Z + @sun-typeface/suit@2.0.5
2025-12-14T15:16:37.515Z + @sveltejs/adapter-auto@7.0.0
2025-12-14T15:16:37.515Z + @sveltejs/kit@2.49.2
2025-12-14T15:16:37.516Z + @sveltejs/vite-plugin-svelte@6.2.1
2025-12-14T15:16:37.518Z + @tailwindcss/forms@0.5.10
2025-12-14T15:16:37.518Z + @tailwindcss/vite@4.1.18
2025-12-14T15:16:37.519Z + @types/node@24.10.4 (v25.0.2 available)
2025-12-14T15:16:37.521Z + eslint@9.39.2
2025-12-14T15:16:37.521Z + eslint-config-prettier@10.1.8
2025-12-14T15:16:37.521Z + eslint-plugin-svelte@3.13.1
2025-12-14T15:16:37.521Z + globals@16.5.0
2025-12-14T15:16:37.524Z + jose@6.1.3
2025-12-14T15:16:37.527Z + prettier@3.7.4
2025-12-14T15:16:37.527Z + prettier-plugin-svelte@3.4.0
2025-12-14T15:16:37.528Z + prettier-plugin-tailwindcss@0.7.2
2025-12-14T15:16:37.528Z + svelte@5.46.0
2025-12-14T15:16:37.528Z + svelte-check@4.3.4
2025-12-14T15:16:37.530Z + tailwindcss@4.1.18
2025-12-14T15:16:37.530Z + typescript@5.9.3
2025-12-14T15:16:37.531Z + typescript-eslint@8.49.0
2025-12-14T15:16:37.531Z + valibot@1.2.0
2025-12-14T15:16:37.531Z + vite@7.2.7
2025-12-14T15:16:37.531Z + wrangler@4.54.0
2025-12-14T15:16:37.531Z
2025-12-14T15:16:37.531Z 233 packages installed [12.14s]
2025-12-14T15:16:37.671Z Executing user build command: node --run build
2025-12-14T15:16:48.470Z vite v7.2.7 building ssr environment for production...
2025-12-14T15:16:48.514Z transforming...
2025-12-14T15:16:49.743Z ✓ 206 modules transformed.
2025-12-14T15:16:49.846Z rendering chunks...
2025-12-14T15:16:50.453Z vite v7.2.7 building client environment for production...
2025-12-14T15:16:50.459Z transforming...
2025-12-14T15:16:51.414Z ✓ 168 modules transformed.
2025-12-14T15:16:51.488Z rendering chunks...
2025-12-14T15:16:51.548Z computing gzip size...
2025-12-14T15:16:51.561Z .svelte-kit/output/client/_app/version.json 0.03 kB │ gzip: 0.05 kB
2025-12-14T15:16:51.561Z .svelte-kit/output/client/.vite/manifest.json 3.12 kB │ gzip: 0.63 kB
2025-12-14T15:16:51.561Z .svelte-kit/output/client/_app/immutable/assets/SUIT-Variable.gqD86R3M.woff2 624.54 kB
2025-12-14T15:16:51.561Z .svelte-kit/output/client/_app/immutable/assets/2.DbZHCSLt.css 0.36 kB │ gzip: 0.24 kB
2025-12-14T15:16:51.562Z .svelte-kit/output/client/_app/immutable/assets/0.CHko16eK.css 13.33 kB │ gzip: 3.54 kB
2025-12-14T15:16:51.562Z .svelte-kit/output/client/_app/immutable/entry/start.RWU3hlsv.js 0.08 kB │ gzip: 0.09 kB
2025-12-14T15:16:51.562Z .svelte-kit/output/client/_app/immutable/chunks/B7OwilHR.js 0.11 kB │ gzip: 0.13 kB
2025-12-14T15:16:51.562Z .svelte-kit/output/client/_app/immutable/chunks/Ba1bqYIH.js 0.18 kB │ gzip: 0.14 kB
2025-12-14T15:16:51.562Z .svelte-kit/output/client/_app/immutable/chunks/BiDYnakw.js 0.35 kB │ gzip: 0.26 kB
2025-12-14T15:16:51.562Z .svelte-kit/output/client/_app/immutable/nodes/1.AS4O5xbF.js 0.86 kB │ gzip: 0.52 kB
2025-12-14T15:16:51.563Z .svelte-kit/output/client/_app/immutable/nodes/0.BcHLcWbe.js 5.49 kB │ gzip: 2.90 kB
2025-12-14T15:16:51.563Z .svelte-kit/output/client/_app/immutable/entry/app.WWYurSqw.js 6.52 kB │ gzip: 3.10 kB
2025-12-14T15:16:51.563Z .svelte-kit/output/client/_app/immutable/chunks/ChRcIiss.js 6.52 kB │ gzip: 3.04 kB
2025-12-14T15:16:51.563Z .svelte-kit/output/client/_app/immutable/nodes/2.B6DGeXcR.js 28.62 kB │ gzip: 11.51 kB
2025-12-14T15:16:51.563Z .svelte-kit/output/client/_app/immutable/chunks/DB_qSe21.js 29.06 kB │ gzip: 11.39 kB
2025-12-14T15:16:51.563Z .svelte-kit/output/client/_app/immutable/chunks/onhwaM3W.js 33.62 kB │ gzip: 12.92 kB
2025-12-14T15:16:51.563Z ✓ built in 1.11s
2025-12-14T15:16:52.145Z vite v7.2.7 building client environment for production...
2025-12-14T15:16:52.152Z transforming...
2025-12-14T15:16:52.157Z ✓ 2 modules transformed.
2025-12-14T15:16:52.162Z rendering chunks...
2025-12-14T15:16:52.163Z computing gzip size...
2025-12-14T15:16:52.164Z .svelte-kit/output/client/service-worker.mjs 1.17 kB │ gzip: 0.56 kB
2025-12-14T15:16:52.166Z ✓ built in 18ms
2025-12-14T15:16:52.166Z .svelte-kit/output/server/.vite/manifest.json 4.69 kB
2025-12-14T15:16:52.166Z .svelte-kit/output/server/_app/immutable/assets/SUIT-Variable.gqD86R3M.woff2 624.54 kB
2025-12-14T15:16:52.166Z .svelte-kit/output/server/_app/immutable/assets/_page.DbZHCSLt.css 0.36 kB
2025-12-14T15:16:52.168Z .svelte-kit/output/server/_app/immutable/assets/_layout.BwjYcKCn.css 13.35 kB
2025-12-14T15:16:52.168Z .svelte-kit/output/server/entries/pages/_page.ts.js 0.06 kB
2025-12-14T15:16:52.168Z .svelte-kit/output/server/chunks/remote-14dkmo.js 0.06 kB
2025-12-14T15:16:52.168Z .svelte-kit/output/server/chunks/environment.js 0.19 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/equality.js 0.33 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/entries/fallbacks/error.svelte.js 0.35 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/internal.js 0.38 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/server.js 0.48 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/index2.js 1.12 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/utils.js 1.15 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/ids.remote.js 1.22 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/hooks.server.js 1.24 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/shared.js 1.34 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/entries/pages/_layout.svelte.js 1.90 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/entries/pages/_page.svelte.js 2.43 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/async.js 3.13 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/remote-entry.js 4.47 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/form.js 6.76 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/exports.js 6.97 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/query.js 8.36 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/form-utils.js 16.45 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/index.js 31.25 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/chunks/internal.js 76.48 kB
2025-12-14T15:16:52.169Z .svelte-kit/output/server/index.js 126.61 kB
2025-12-14T15:16:52.170Z ✓ built in 3.67s
2025-12-14T15:16:52.170Z
2025-12-14T15:16:52.170Z Run npm run preview to preview your production build locally.
2025-12-14T15:16:52.174Z
2025-12-14T15:16:52.174Z > Using @sveltejs/adapter-auto
2025-12-14T15:16:52.174Z Could not detect a supported production environment. See https://svelte.dev/docs/kit/adapters to learn how to configure your app to run on the platform of your choosing
2025-12-14T15:16:52.174Z ✔ done
2025-12-14T15:16:52.260Z Success: Build command completed
2025-12-14T15:16:52.412Z Executing user deploy command: npx wrangler deploy
2025-12-14T15:16:53.813Z
2025-12-14T15:16:53.813Z ⛅️ wrangler 4.54.0
2025-12-14T15:16:53.814Z ───────────────────
2025-12-14T15:16:53.834Z
2025-12-14T15:16:53.886Z ✘ [ERROR] The entry-point file at ".svelte-kit/cloudflare/_worker.js" was not found.
2025-12-14T15:16:53.887Z
2025-12-14T15:16:53.887Z
2025-12-14T15:16:53.913Z
2025-12-14T15:16:53.913Z Cloudflare collects anonymous telemetry about your usage of Wrangler. Learn more at https://github.com/cloudflare/workers-sdk/tree/main/packages/wrangler/telemetry.md
2025-12-14T15:16:53.931Z 🪵 Logs were written to "/opt/buildhome/.config/.wrangler/logs/wrangler-2025-12-14_15-16-53_345.log"
2025-12-14T15:16:54.158Z Failed: error occurred while running deploy command
System Info
CI
Severity
annoyance
Additional Information
No response
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the linked reproduction and the @sveltejs/adapter-auto output, then run the Cloudflare build and npx wrangler deploy commands described in the logs. Trace why the Cloudflare environment is not detected when only .node-version is present and no lockfile exists. Done means the adapter detects Cloudflare Workers and generates .svelte-kit/cloudflare/_worker.js so deployment succeeds.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- javascript
- Domain
- cloud, devops
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100