Cannot start nuxt: Package subpath './nuxt' is not defined by "exports"

[jclaessens97]

I setup a nuxt module following the (limited) docs and the module starter template.

The playground works, but whenever I want to build and use it in my main nuxt application (using pnpm and file:../ui), I get following error output:

Nuxt CLI v3.0.0-rc.8                                                  09:15:59
                                                                      09:16:02
  > Local:    http://localhost:8080/
  > Network:  http://10.11.12.43:8080/


 ERROR  Cannot start nuxt:  Package subpath './nuxt' is not defined by "exports" in /Users/jclaessens/dev/proj/packages/nuxt3_web/node_modules/@skyebase/ui/package.json

  at new NodeError (node:internal/errors:371:5)
  at throwExportsNotFound (node:internal/modules/esm/resolve:453:9)
  at packageExportsResolve (node:internal/modules/esm/resolve:729:3)
  at resolveExports (node:internal/modules/cjs/loader:482:36)
  at Function.Module._findPath (node:internal/modules/cjs/loader:522:31)
  at Function.Module._resolveFilename (node:internal/modules/cjs/loader:919:27)
  at Function.resolve (node:internal/modules/cjs/helpers:108:19)
  at Function._resolve [as resolve] (/Users/jclaessens/dev/proj/node_modules/.pnpm/jiti@1.14.0/node_modules/jiti/dist/jiti.js:1:108226)
  at resolveModule (/Users/jclaessens/dev/proj/node_modules/.pnpm/@nuxt+kit@3.0.0-rc.8_webpack@5.74.0/node_modules/@nuxt/kit/dist/index.mjs:253:29)
  at normalizeModule (/Users/jclaessens/dev/proj/node_modules/.pnpm/@nuxt+kit@3.0.0-rc.8_webpack@5.74.0/node_modules/@nuxt/kit/dist/index.mjs:462:18)

npx nuxi info output:

❯ npx nuxi info
Nuxt CLI v3.0.0-rc.8                                                                                                                                                                  09:30:16
RootDir: /Users/jclaessens/dev/proj/packages/nuxt3_web                                                                                                                    09:30:18
Nuxt project info:                                                                                                                                                                    09:30:18

------------------------------
- Operating System: `Darwin`
- Node Version:     `v16.14.0`
- Nuxt Version:     `3.0.0-rc.8`
- Package Manager:  `pnpm@7.9.0`
- Builder:          `vite`
- User Config:      `ssr`, `typescript`, `css`, `modules`, `runtimeConfig`
- Runtime Modules:  `@vueuse/nuxt@8.9.4`, `proj/nuxt@1.0.0`
- Build Modules:    `-`
------------------------------

👉 Report an issue: https://github.com/nuxt/framework/issues/new                                                                                                                      09:30:18

👉 Suggest an improvement: https://github.com/nuxt/framework/discussions/new

👉 Read documentation: https://v3.nuxtjs.org

I configured the module as proj/ui/nuxt and I'm sure I build it first using the prepack command.

Any pointers on what it could be?

(I replaced the real namespaced project name with proj)

[danielroe]

Impossible to say exactly without seeing your code, but you likely need to add a subpath exports like:

  "exports": {
    // ...
    "./nuxt": "./dist/nuxt.mjs"
  },

See more at https://nodejs.org/api/packages.html#packages_subpath_exports.

[jclaessens97]

Thanks for your answer.
I can try to make a minimal repro later today if it's something that hasn't come up yet...

As for the exports I just used the "main" and direct it to the built module files:

"type": "module",
  "exports": {
    ".": {
      "import": "./dist/module.mjs",
      "require": "./dist/module.cjs"
    }
  },
  "main": "./dist/module.cjs",
  "types": "./dist/types.d.ts",
  "files": [
    "dist"
  ],

My module.ts looks like this:

import {
  defineNuxtModule,
  addComponentsDir,
  addPlugin,
  createResolver,
} from '@nuxt/kit';

export default defineNuxtModule({
  meta: {
    name: 'proj/ui',
    compatibility: {
      nuxt: '^3.0.0',
    },
  },
  setup(options, nuxt) {
    const { resolve } = createResolver(import.meta.url);

    nuxt.options.css = [
      'primevue/resources/themes/md-light-deeppurple/theme.css',
      'primevue/resources/primevue.min.css',
      'primeicons/primeicons.css',
      'primeflex/primeflex.css',
      ...nuxt.options.css,
    ];
    nuxt.options.build.transpile.push('primevue');

    const pluginDir = resolve(__dirname, 'runtime', 'plugins');
    addPlugin(resolve(pluginDir, 'vue-country-flag.plugin.ts'));
    addPlugin(resolve(pluginDir, 'mapbox.plugin.ts'));
    addPlugin(resolve(pluginDir, 'primevue.plugin.ts'));
    addPlugin(resolve(pluginDir, 'primevue.plugin.client.ts'));

    addComponentsDir({
      path: resolve(__dirname, 'runtime', 'components'),
      prefix: 'sb',
    });
  },
});

And then runtime contains just plugins and components using primevue as plain vue/nuxt code.

If you still need more info to investigate, please let me know then I'll try to setup a minimal repro.

[danielroe]

Yes, a reproduction would be helpful, thanks.

[jclaessens97]

Added a repro on my personal github in the following repository: https://github.com/jclaessens97/nuxt-module-repro

[danielroe]

Yes, if you are importing from @proj/ui/nuxt you need a subpath export: #14602

But you don't need it. Just remove the /nuxt suffix and you should be good to go:

-   modules: ['@proj/ui/nuxt'],
+   modules: ['@proj/ui'],

[jclaessens97]

In the same repro I tried removing the /nuxt suffix, but then another (related?) error arises:

Failed to resolve import "/Users/jclaessens/dev/github/nuxt-module-repro/node_modules/.pnpm/file+packages+lib+ui_ufy6fydyuyaiiyys52pg2bdj2m/node_modules/@proj/ui/dist/runtime/plugins/primevue.plugin.client.ts" from "virtual:nuxt:/Users/jclaessens/dev/github/nuxt-module-repro/packages/nuxt-app/.nuxt/plugins/client.mjs". Does the file exist?

It's not only the primevue plugin. I have the same with all plugins. It always throws on the first plugin I try to add (bottom to top in the module.ts file).

[danielroe]

Great! (in response to a message that read: "And now it seems to be working fine 👌")

[jclaessens97]

Great! (in response to a message that read: "And now it seems to be working fine 👌")

Yeah, my bad, I removed it since I was a bit too quick 😅

I managed to get it working, but there is still something off.

For the repro to work, I have to run dev:prepare before prepack, and then install it in the main app, so not sure if this is intended behavior or not. If it is, then it's working correctly I suppose..

I'm still investigating though because in my real app it's still not working.