Broken legacy build

Describe the bug

Building with plugin-legacy seems to be broken

Reproduction

1. create new project with yarn create @vitejs/app (template - react + ts)
2. add @vitejs/plugin-legacy - yarn add -D @vitejs/plugin-legacy
3. update vite.config.ts -

import { defineConfig } from 'vite';
import legacy from '@vitejs/plugin-legacy';
import reactRefresh from '@vitejs/plugin-react-refresh';

// https://vitejs.dev/config/
export default defineConfig({
  plugins: [legacy(), reactRefresh()],
});

1. run yarn build // error

System Info

• vite version: 2.0.5
• Operating System: Windows 10
• Node version: 14.15.5
• Package manager (npm/yarn/pnpm) and version: yarn@1.22.10

Logs (Optional if provided reproduction)

1. Run vite build with the --debug flag.

$ tsc && vite build --debug
  vite:config bundled config file loaded in 201ms +0ms
  vite:config using resolved config: {
  vite:config   plugins: [
  vite:config     'alias',
  vite:config     'react-refresh',
  vite:config     'vite:dynamic-import-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     'legacy-generate-polyfill-chunk',
  vite:config     'legacy-env',
  vite:config     'vite:define',
  vite:config     'vite:css-post',
  vite:config     'vite:build-html',
  vite:config     'commonjs',
  vite:config     'vite:data-uri',
  vite:config     'rollup-plugin-dynamic-import-variables',
  vite:config     'legacy-post-process',
  vite:config     'vite:import-analysis',
  vite:config     'vite:esbuild-transpile',
  vite:config     'vite:terser',
  vite:config     'vite:reporter'
  vite:config   ],
  vite:config   build: {
  vite:config     target: [ 'es2019', 'edge16', 'firefox60', 'chrome61', 'safari11' ],
  vite:config     polyfillDynamicImport: true,
  vite:config     outDir: 'dist',
  vite:config     assetsDir: 'assets',
  vite:config     assetsInlineLimit: 4096,
  vite:config     cssCodeSplit: true,
  vite:config     sourcemap: false,
  vite:config     rollupOptions: { output: [Array] },
  vite:config     commonjsOptions: { include: [Array], extensions: [Array] },
  vite:config     minify: 'terser',
  vite:config     terserOptions: {},
  vite:config     cleanCssOptions: {},
  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   },
  vite:config   define: { 'import.meta.env.LEGACY': '__VITE_IS_LEGACY__' },
  vite:config   configFile: 'C:/Users/azymov/Documents/projects/vite-project/vite.config.ts',
  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     build: {}
  vite:config   },
  vite:config   root: 'C:/Users/azymov/Documents/projects/vite-project',
  vite:config   base: '/',
  vite:config   resolve: { dedupe: undefined, alias: [ [Object] ] },
  vite:config   publicDir: 'C:\\Users\\azymov\\Documents\\projects\\vite-project\\public',
  vite:config   command: 'build',
  vite:config   mode: 'production',
  vite:config   isProduction: true,
  vite:config   optimizeCacheDir: 'C:\\Users\\azymov\\Documents\\projects\\vite-project\\node_modules\\.vite',
  vite:config   server: {},
  vite:config   env: { BASE_URL: '/', MODE: 'production', DEV: false, PROD: true },
  vite:config   assetsInclude: [Function: assetsInclude],
  vite:config   logger: {
  vite:config     hasWarned: false,
  vite:config     info: [Function: info],
  vite:config     warn: [Function: warn],
  vite:config     error: [Function: error],
  vite:config     clearScreen: [Function: clearScreen]
  vite:config   },
  vite:config   createResolver: [Function: createResolver]
  vite:config } +5ms
vite v2.0.5 building for production...
✓ 21 modules transformed.
[legacy-post-process] [BABEL] unknown: .plugins[36][0] must be a string, object, function
error during build:
Error: [BABEL] unknown: .plugins[36][0] must be a string, object, function
    at assertPluginTarget (C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67416:12)
    at assertPluginItem (C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67390:6)
    at C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67373:15
    at Array.forEach (<anonymous>)
    at assertPluginList (C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67372:10)
    at C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67591:6
    at Array.forEach (<anonymous>)
    at validateNested (C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67567:22)
    at validate$3 (C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67558:11)
    at C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:69754:15

1. Provide the error log here.

$ tsc && vite build
vite v2.0.5 building for production...
✓ 21 modules transformed.
[legacy-post-process] [BABEL] unknown: .plugins[36][0] must be a string, object, function
error during build:
Error: [BABEL] unknown: .plugins[36][0] must be a string, object, function
    at assertPluginTarget (C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67416:12)
    at assertPluginItem (C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67390:6)   
    at C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67373:15
    at Array.forEach (<anonymous>)
    at assertPluginList (C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67372:10)  
    at C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67591:6
    at Array.forEach (<anonymous>)
    at validateNested (C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67567:22)    
    at validate$3 (C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:67558:11)
    at C:\Users\azymov\Documents\projects\vite-project\node_modules\@babel\standalone\babel.js:69754:15

[pedrodim]

@Eazymov since you’re using yarn, as a temporal workaround similar to the one on #2442, you can try and use selective resolution to pin the version. https://classic.yarnpkg.com/en/docs/selective-version-resolutions/#toc-how-to-use-it

[patak-dev]

Closing as duplicate of #2442