[BUG] Error Could not resolve when npm run deploy

[ton11797]

Describe the bug

Error when try to run npm run deploy

Next.js version : 15.3.1
@opennextjs/cloudflare version: 1.0.2
@opennextjs/aws version: ^3.6.1

┌─────────────────────────────────┐
│ OpenNext — Building Next.js app │
└─────────────────────────────────┘


> cf-bug@0.1.0 build
> next build

Using vars defined in .dev.vars
   ▲ Next.js 15.3.1
   - Environments: .env

Using vars defined in .dev.vars
   Creating an optimized production build ...
Using vars defined in .dev.vars
Using vars defined in .dev.vars
Using vars defined in .dev.vars
 ✓ Compiled successfully in 0ms
 ✓ Linting and checking validity of types    
 ✓ Collecting page data    
 ✓ Generating static pages (6/6)
 ✓ Collecting build traces    
 ✓ Finalizing page optimization    

Route (app)                                 Size  First Load JS
┌ ○ /                                    5.63 kB         107 kB
├ ○ /_not-found                            977 B         102 kB
└ ƒ /test                                  136 B         101 kB
+ First Load JS shared by all             101 kB
  ├ chunks/4bd1b696-67ee12fb04071d3b.js  53.2 kB
  ├ chunks/684-71b0b1461a73105d.js       45.9 kB
  └ other shared chunks (total)          1.96 kB


○  (Static)   prerendered as static content
ƒ  (Dynamic)  server-rendered on demand


┌──────────────────────────────┐
│ OpenNext — Generating bundle │
└──────────────────────────────┘

Bundling middleware function...
Bundling static assets...
Bundling cache assets...
Building server function: default...
Applying code patches: 3.695s
# copyPackageTemplateFiles
⚙️ Bundling the OpenNext server...

X [ERROR] Could not resolve "@libsql/isomorphic-ws"

    .open-next/server-functions/default/node_modules/@libsql/hrana-client/lib-esm/index.js:1:26:
      1 │ import { WebSocket } from "@libsql/isomorphic-ws";
        ╵                           ~~~~~~~~~~~~~~~~~~~~~~~

  The module "./web.mjs" was not found on the file system:

    .open-next/server-functions/default/node_modules/@libsql/isomorphic-ws/package.json:24:19:
      24 │         "workerd": "./web.mjs",
         ╵                    ~~~~~~~~~~~

  You can mark the path "@libsql/isomorphic-ws" as external to exclude it from the bundle, which
  will remove this error and leave the unresolved path in the bundle.

C:\Users\Denice\Documents\git\cf-bug\node_modules\esbuild\lib\main.js:1463
  let error = new Error(text);
              ^

Error: Build failed with 1 error:
.open-next/server-functions/default/node_modules/@libsql/hrana-client/lib-esm/index.js:1:26: ERROR: Could not resolve "@libsql/isomorphic-ws"
    at failureErrorWithLog (C:\Users\Denice\Documents\git\cf-bug\node_modules\esbuild\lib\main.js:1463:15)
    at C:\Users\Denice\Documents\git\cf-bug\node_modules\esbuild\lib\main.js:924:25
    at runOnEndCallbacks (C:\Users\Denice\Documents\git\cf-bug\node_modules\esbuild\lib\main.js:1303:45)
    at buildResponseToResult (C:\Users\Denice\Documents\git\cf-bug\node_modules\esbuild\lib\main.js:922:7)
    at C:\Users\Denice\Documents\git\cf-bug\node_modules\esbuild\lib\main.js:949:16
    at responseCallbacks.<computed> (C:\Users\Denice\Documents\git\cf-bug\node_modules\esbuild\lib\main.js:601:9)
    at handleIncomingPacket (C:\Users\Denice\Documents\git\cf-bug\node_modules\esbuild\lib\main.js:656:12)
    at Socket.readFromStdout (C:\Users\Denice\Documents\git\cf-bug\node_modules\esbuild\lib\main.js:579:7)
    at Socket.emit (node:events:524:28)
    at Socket.emit (node:domain:489:12) {
  errors: [Getter/Setter],
  warnings: [Getter/Setter]
}

Node.js v22.13.1

Steps to reproduce

1. npm create cloudflare@latest -- my-next-app --framework=next <---- all default
2. setup basic drizzle with libsql
3. simple route to call get data from db
4. npm run deploy

Expected behavior

Able to build and deploy

@opennextjs/cloudflare version

1.0.2

Wrangler version

4.14.4

next info output

Operating System:
  Platform: win32
  Arch: x64
  Version: Windows 11 Pro
  Available memory (MB): 130199
  Available CPU cores: 24
Binaries:
  Node: 22.13.1
  npm: 10.9.2
  Yarn: N/A
  pnpm: N/A
Relevant Packages:
  next: 15.3.1 // There is a newer version (15.3.2) available, upgrade recommended!
  eslint-config-next: 15.3.1
  react: 19.1.0
  react-dom: 19.1.0
  typescript: 5.8.3
Next.js Config:
  output: N/A
 ⚠ There is a newer version (15.3.2) available, upgrade recommended!
   Please try the latest canary version (`npm install next@canary`) to confirm the issue still exists before creating a new issue.
   Read more - https://nextjs.org/docs/messages/opening-an-issue

Additional context

Fix by change @opennextjs/cloudflare version to 1.0.0-beta.4

[vicb]

See https://opennext.js.org/cloudflare/howtos/workerd#workerd-specific-code

It looks like @libsql/isomorphic-ws has workerd specific code so you need to add it in the serverExternalPackages key of your next.config.ts

[ton11797]

I did add it to serverExternalPackages but still got same error.

next.config.ts

const nextConfig: NextConfig = {
  /* config options here */
  serverExternalPackages:["@libsql/isomorphic-ws"],
};

Error

# copyPackageTemplateFiles
⚙️ Bundling the OpenNext server...

X [ERROR] Could not resolve "@libsql/isomorphic-ws"

    .open-next/server-functions/default/node_modules/@libsql/hrana-client/lib-esm/index.js:1:26:
      1 │ import { WebSocket } from "@libsql/isomorphic-ws";
        ╵                           ~~~~~~~~~~~~~~~~~~~~~~~

  The module "./web.mjs" was not found on the file system:

    .open-next/server-functions/default/node_modules/@libsql/isomorphic-ws/package.json:24:19:
      24 │         "workerd": "./web.mjs",
         ╵                    ~~~~~~~~~~~

  You can mark the path "@libsql/isomorphic-ws" as external to exclude it from the bundle, which
  will remove this error and leave the unresolved path in the bundle.

C:\Users\Denice\Documents\git\d\oc-pop\node_modules\esbuild\lib\main.js:1463
  let error = new Error(text);
              ^

Error: Build failed with 1 error:

@libsql/isomorphic-ws package.json

{
  "name": "@libsql/isomorphic-ws",
  "version": "0.1.5",
  "keywords": ["ws", "websocket", "isomorphic", "node", "deno", "workers"],
  "description": "Isomorphic WebSockets in Node, Bun, Deno and Cloudflare Workers",
  "repository": {
    "type": "git",
    "url": "https://github.com/libsql/isomorphic-ts.git",
    "directory": "isomorphic-ws"
  },
  "homepage": "https://github.com/libsql/isomorphic-ts/tree/main/isomorphic-ws",
  "authors": [
    "Jan Špaček <honza@chiselstrike.com>"
  ],
  "license": "MIT",

  "main": "node.cjs",
  "types": "index.d.ts",
  "exports": {
    ".": {
      "import": {
        "bun": "./web.mjs",
        "deno": "./web.mjs",
        "workerd": "./web.mjs",
        "node": "./node.mjs",
        "default": "./web.mjs"
      },
      "require": {
        "bun": "./web.cjs",
        "deno": "./web.cjs",
        "workerd": "./web.cjs",
        "node": "./node.cjs",
        "default": "./web.cjs"
      }
    }
  },
  "files": ["*.mjs", "*.cjs", "*.js", "*.d.ts"],

  "dependencies": {
    "ws": "^8.13.0",
    "@types/ws": "^8.5.4"
  }
}

[vicb]

Could you create a minimal repro and add a link to the GH repository here?

[ton11797]

https://github.com/ton11797/cf-bug

[sommeeeer]

Looks like a Windows problem

[vicb]

Good catch @sommeeeer

Operating System:
  Platform: win32
  Arch: x64
  Version: Windows 11 Pro

WSL is the only supported way to build on windows, is that what you use @ton11797 ?

[wonyx]

I had the same problem.
I set @libsql/isomorphic-ws to serverExternalPackages in next.config.ts, I was able to build.

const nextConfig: NextConfig = {
	/* config options here */
	serverExternalPackages: ["@libsql/isomorphic-ws"],
};

REF: https://nextjs.org/docs/app/api-reference/config/next-config-js/serverExternalPackages

My machine is ubuntu 24.04 x86_64.

[mohsentaleb]

I'm on WSL2 - Ubuntu-20.04
Using opennextjs-cloudflare v1.0.2 and I'm having a similar problem with package jose:

⚙️ Bundling the OpenNext server...

✘ [ERROR] Could not resolve "jose"

    .open-next/server-functions/default/node_modules/jwks-rsa/src/integrations/passport.js:1:21:
      1 │ const jose = require('jose');
        ╵                      ~~~~~~

  The module "./dist/browser/index.js" was not found on the file system:

    .open-next/server-functions/default/node_modules/jwks-rsa/node_modules/jose/package.json:68:17:
      68 │       "workerd": "./dist/browser/index.js",
         ╵                  ~~~~~~~~~~~~~~~~~~~~~~~~~

  You can mark the path "jose" as external to exclude it from the bundle, which will remove this
  error. You can also surround this "require" call with a try/catch block to handle this failure at
  run-time instead of bundle-time.

Adding serverExternalPackages: ["jose"] to my next.config.js did the job.

[vicb]

https://github.com/ton11797/cf-bug

When I clone the repo and and run npm run preview, I don't see any issue (on MacOS):

Are there any particular steps to trigger the bug?

If not, this might be related to not using WSL as mentioned above.