Cannot import `Vue` (no default export defined)

[brendanarnold]

Describe the bug

After scaffolding a Vue app, trying to do a default import of Vue from a component fails saying that the default export is not defined for 'vue'

Reproduction

1. Scaffold a new vue project using vite cli
2. Add import Vue from 'vue' to the top of the script area of HelloWorld.vue
3. Hot reloading fails

example HeloWorld.js

System Info

System:
    OS: macOS 11.4
    CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
    Memory: 56.42 MB / 16.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 15.5.0 - ~/.nvm/versions/node/v15.5.0/bin/node
    npm: 7.3.0 - ~/.nvm/versions/node/v15.5.0/bin/npm
  Browsers:
    Chrome: 92.0.4515.159
    Firefox: 91.0
    Safari: 14.1.1
  npmPackages:
    @vitejs/plugin-vue: ^1.3.0 => 1.4.0 
    vite: ^2.4.4 => 2.5.0 

Used Package Manager

npm

Logs

(base) brendan@MacBook-Pro front-end % npx vite --debug
  vite:config bundled config file loaded in 157ms +0ms
[dotenv][DEBUG] did not match key and value when parsing line 4: 
  vite:config using resolved config: {
  vite:config   plugins: [
  vite:config     'vite:pre-alias',
  vite:config     'alias',
  vite:config     'vite:modulepreload-polyfill',
  vite:config     'vite:resolve',
  vite:config     'vite:html',
  vite:config     'vite:css',
  vite:config     'vite:esbuild',
  vite:config     'vite:json',
  vite:config     'vite:wasm',
  vite:config     'vite:worker',
  vite:config     'vite:asset',
  vite:config     'vite:vue',
  vite:config     'vite:define',
  vite:config     'vite:css-post',
  vite:config     'vite:client-inject',
  vite:config     'vite:import-analysis'
  vite:config   ],
  vite:config   server: { fs: { strict: undefined, allow: [Array] } },
  vite:config   define: { __VUE_OPTIONS_API__: true, __VUE_PROD_DEVTOOLS__: false },
  vite:config   ssr: { external: [ 'vue', '@vue/server-renderer' ] },
  vite:config   configFile: '/Users/brendan/Developer/open-bookmarks/front-end/vite.config.js',
  vite:config   configFileDependencies: [ 'vite.config.js' ],
  vite:config   inlineConfig: {
  vite:config     root: undefined,
  vite:config     base: undefined,
  vite:config     mode: undefined,
  vite:config     configFile: undefined,
  vite:config     logLevel: undefined,
  vite:config     clearScreen: undefined,
  vite:config     server: { fs: [Object] }
  vite:config   },
  vite:config   root: '/Users/brendan/Developer/open-bookmarks/front-end',
  vite:config   base: '/',
  vite:config   resolve: { dedupe: undefined, alias: [ [Object], [Object] ] },
  vite:config   publicDir: '/Users/brendan/Developer/open-bookmarks/front-end/public',
  vite:config   cacheDir: '/Users/brendan/Developer/open-bookmarks/front-end/node_modules/.vite',
  vite:config   command: 'serve',
  vite:config   mode: 'development',
  vite:config   isProduction: false,
  vite:config   build: {
  vite:config     target: [ 'es2019', 'edge88', 'firefox78', 'chrome87', 'safari13.1' ],
  vite:config     polyfillModulePreload: true,
  vite:config     outDir: 'dist',
  vite:config     assetsDir: 'assets',
  vite:config     assetsInlineLimit: 4096,
  vite:config     cssCodeSplit: true,
  vite:config     sourcemap: false,
  vite:config     rollupOptions: {},
  vite:config     commonjsOptions: { include: [Array], extensions: [Array] },
  vite:config     dynamicImportVarsOptions: { warnOnError: true, exclude: [Array] },
  vite:config     minify: 'terser',
  vite:config     terserOptions: {},
  vite:config     write: true,
  vite:config     emptyOutDir: null,
  vite:config     manifest: false,
  vite:config     lib: false,
  vite:config     ssr: false,
  vite:config     ssrManifest: false,
  vite:config     brotliSize: true,
  vite:config     chunkSizeWarningLimit: 500,
  vite:config     watch: null
  vite:config   },
  vite:config   env: { BASE_URL: '/', MODE: 'development', DEV: true, PROD: false },
  vite:config   assetsInclude: [Function: assetsInclude],
  vite:config   logger: {
  vite:config     hasWarned: false,
  vite:config     info: [Function: info],
  vite:config     warn: [Function: warn],
  vite:config     warnOnce: [Function: warnOnce],
  vite:config     error: [Function: error],
  vite:config     clearScreen: [Function: clearScreen],
  vite:config     hasErrorLogged: [Function: hasErrorLogged]
  vite:config   },
  vite:config   createResolver: [Function: createResolver],
  vite:config   optimizeDeps: { esbuildOptions: { keepNames: undefined } }
  vite:config } +6ms
  vite:deps Hash is consistent. Skipping. Use --force to override. +0ms

  vite v2.5.0 dev server running at:

  > Local: http://localhost:3000/
  > Network: use `--host` to expose

  ready in 330ms.

  vite:time 1ms   / +0ms
  vite:spa-fallback Rewriting GET / to /index.html +0ms
  vite:time 19ms  /index.html +30ms
  vite:resolve 2ms   /@vite/client -> /Users/brendan/Developer/open-bookmarks/front-end/node_modules/vite/dist/client/client.mjs +0ms
  vite:resolve 0ms   /src/main.js -> /Users/brendan/Developer/open-bookmarks/front-end/src/main.js +4ms
  vite:load 4ms   [fs] /src/main.js +0ms
  vite:resolve 0ms   vue -> /Users/brendan/Developer/open-bookmarks/front-end/node_modules/.vite/vue.js?v=c4954b3a +8ms
  vite:resolve 1ms   /node_modules/.vite/vue.js?v=c4954b3a -> /Users/brendan/Developer/open-bookmarks/front-end/node_modules/.vite/vue.js?v=c4954b3a +1ms
  vite:resolve 0ms   ./App.vue -> /Users/brendan/Developer/open-bookmarks/front-end/src/App.vue +0ms
  vite:resolve 1ms   /src/App.vue -> /Users/brendan/Developer/open-bookmarks/front-end/src/App.vue +1ms
  vite:transform 6ms   /src/main.js +0ms
  vite:time 12ms  /src/main.js +43ms
  vite:load 14ms  [fs] /@vite/client +8ms
  vite:resolve 0ms   @vite/env -> /Users/brendan/Developer/open-bookmarks/front-end/node_modules/vite/dist/client/env.mjs +9ms
  vite:resolve 0ms   /node_modules/vite/dist/client/env.mjs -> /Users/brendan/Developer/open-bookmarks/front-end/node_modules/vite/dist/client/env.mjs +1ms
  vite:transform 6ms   /@vite/client +10ms
  vite:time 28ms  /@vite/client +10ms
  vite:load 2ms   [fs] /node_modules/vite/dist/client/env.mjs +52ms
  vite:rewrite 1ms   [no imports] node_modules/vite/dist/client/env.mjs +0ms
  vite:transform 3ms   /node_modules/vite/dist/client/env.mjs +46ms
  vite:time 6ms   /node_modules/vite/dist/client/env.mjs +46ms
  vite:load 5ms   [fs] /src/App.vue +4ms
  vite:resolve 2ms   ./components/HelloWorld.vue -> /Users/brendan/Developer/open-bookmarks/front-end/src/components/HelloWorld.vue +85ms
  vite:resolve 0ms   /src/components/HelloWorld.vue -> /Users/brendan/Developer/open-bookmarks/front-end/src/components/HelloWorld.vue +0ms
  vite:resolve 0ms   /src/App.vue?vue&type=style&index=0&lang.css -> /Users/brendan/Developer/open-bookmarks/front-end/src/App.vue?vue&type=style&index=0&lang.css +1ms
  vite:hmr [self-accepts] src/App.vue +0ms
  vite:transform 39ms  /src/App.vue +40ms
  vite:time 44ms  /src/App.vue +40ms
  vite:load 0ms   [plugin] /src/App.vue?vue&type=style&index=0&lang.css +47ms
  vite:load 9ms   [fs] /src/components/HelloWorld.vue +7ms
[@vue/compiler-sfc] `defineProps` is a compiler macro and no longer needs to be imported.

  vite:resolve 0ms   /src/components/HelloWorld.vue?vue&type=style&index=0&scoped=true&lang.css -> /Users/brendan/Developer/open-bookmarks/front-end/src/components/HelloWorld.vue?vue&type=style&index=0&scoped=true&lang.css +42ms
  vite:hmr [self-accepts] src/components/HelloWorld.vue +43ms
  vite:transform 27ms  /src/components/HelloWorld.vue +42ms
  vite:time 36ms  /src/components/HelloWorld.vue +42ms
  vite:load 0ms   [plugin] /src/components/HelloWorld.vue?vue&type=style&index=0&scoped=true&lang.css +33ms
  vite:hmr [self-accepts] src/App.vue?vue&type=style&index=0&lang.css +14ms
  vite:transform 48ms  /src/App.vue?vue&type=style&index=0&lang.css +14ms
  vite:time 49ms  /src/App.vue?vue&type=style&index=0&lang.css +14ms
  vite:hmr [self-accepts] src/components/HelloWorld.vue?vue&type=style&index=0&scoped=true&lang.css +8ms
  vite:transform 17ms  /src/components/HelloWorld.vue?vue&type=style&index=0&scoped=true&lang.css +9ms
  vite:time 18ms  /src/components/HelloWorld.vue?vue&type=style&index=0&scoped=true&lang.css +9ms

Validations

• [X] Follow our Code of Conduct
• [X] Read the Contributing Guidelines.
• [X] Read the docs.
• [X] Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• [X] Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/vue-next instead.
• [X] Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• [X] The provided reproduction is a minimal reproducible example of the bug.

[haoqunjiang]

There's no default export in Vue 3. You can use import * as Vue from 'vue', though.