Preserve "[" and "]" in bundle of rollupOptions

[rtritto]

Describe the bug

Having the API routes in ./server/api directory and it needs to be bundled in ./dist/server/api.

Example

Source file ./server/api/user/[id]/(post).ts as the API route file.

Expected

./dist/server/api/user/[id]/(post).mjs

Current

./dist/server/api/user/_id_/(post).mjs

Reproduction

https://github.com/rtritto/vite-preserve

Steps to reproduce

• git clone https://github.com/rtritto/vite-preserve.git
• cd vite-preserve
• yarn
• yarn build or yarn vite build

System Info

System:
    OS: Windows 11 10.0.22631
  Binaries:
    Node: 22.9.0 - C:\Program Files\nodejs\node.EXE
    Yarn: 4.5.3 - C:\Program Files\nodejs\yarn.CMD
    npm: 10.8.3 - C:\Program Files\nodejs\npm.CMD

Used Package Manager

yarn

Logs

Logs

The CJS build of Vite's Node API is deprecated. See https://vite.dev/guide/troubleshooting.html#vite-cjs-node-api-deprecated for more details.
  vite:config bundled config file loaded in 62.49ms +0ms
  vite:config using resolved config: {
  vite:config   cacheDir: 'C:/vite-preserve/.vite',
  vite:config   plugins: [
  vite:config     'vite:build-metadata',
  vite:config     'vite:watch-package-data',
  vite:config     'vite:pre-alias',
  vite:config     'alias',
  vite:config     'vite:modulepreload-polyfill',
  vite:config     'vite:resolve',
  vite:config     'vite:html-inline-proxy',
  vite:config     'vite:css',
  vite:config     'vite:esbuild',
  vite:config     'vite:json',
  vite:config     'vite:wasm-helper',
  vite:config     'vite:worker',
  vite:config     'vite:asset',
  vite:config     'vite:wasm-fallback',
  vite:config     'vite:define',
  vite:config     'vite:css-post',
  vite:config     'vite:build-html',
  vite:config     'vite:worker-import-meta-url',
  vite:config     'vite:asset-import-meta-url',
  vite:config     'vite:force-systemjs-wrap-complete',
  vite:config     'commonjs',
  vite:config     'vite:data-uri',
  vite:config     'vite:rollup-options-plugins',
  vite:config     'vite:dynamic-import-vars',
  vite:config     'vite:import-glob',
  vite:config     'vite-plugin-bundle-files',
  vite:config     'vite:build-import-analysis',
  vite:config     'vite:esbuild-transpile',
  vite:config     'vite:terser',
  vite:config     'vite:manifest',
  vite:config     'vite:ssr-manifest',
  vite:config     'vite:reporter',
  vite:config     'vite:load-fallback'
  vite:config   ],
  vite:config   build: {
  vite:config     target: [ 'es2020', 'edge88', 'firefox78', 'chrome87', 'safari14' ],     
  vite:config     polyfillModulePreload: true,
  vite:config     modulePreload: { polyfill: true },
  vite:config     outDir: 'dist',
  vite:config     assetsDir: 'assets',
  vite:config     assetsInlineLimit: 4096,
  vite:config     sourcemap: false,
  vite:config     terserOptions: {},
  vite:config     rollupOptions: {},
  vite:config     commonjsOptions: { include: [ /node_modules/ ], extensions: [ '.js', '.cjs' ] },
  vite:config     dynamicImportVarsOptions: { warnOnError: true, exclude: [ /node_modules/ ] },
  vite:config     write: true,
  vite:config     emptyOutDir: null,
  vite:config     copyPublicDir: true,
  vite:config     manifest: false,
  vite:config     lib: false,
  vite:config     ssrManifest: false,
  vite:config     ssrEmitAssets: false,
  vite:config     reportCompressedSize: true,
  vite:config     chunkSizeWarningLimit: 500,
  vite:config     watch: null,
  vite:config     cssCodeSplit: true,
  vite:config     minify: 'esbuild',
  vite:config     ssr: false,
  vite:config     emitAssets: true,
  vite:config     createEnvironment: [Function: createEnvironment],
  vite:config     cssTarget: [ 'es2020', 'edge88', 'firefox78', 'chrome87', 'safari14' ],  
  vite:config     cssMinify: true
  vite:config   },
  vite:config   environments: {
  vite:config     client: {
  vite:config       define: undefined,
  vite:config       resolve: {
  vite:config         externalConditions: [ 'node' ],
  vite:config         extensions: [ '.mjs', '.js', '.ts', '.jsx', '.tsx', '.json' ],       
  vite:config         dedupe: [],
  vite:config         noExternal: [],
  vite:config         external: [],
  vite:config         preserveSymlinks: false,
  vite:config         alias: [
  vite:config           {
  vite:config             find: /^\/?@vite\/env/,
  vite:config             replacement: '/@fs/C:/vite-preserve/.yarn/__virtual__/vite-virtual-dbc7c14500/4/Users/<USER>/AppData/Local/Yarn/Berry/cache/vite-npm-6.0.5-7387b23353-10c0.zip/node_modules/vite/dist/client/env.mjs'
  vite:config           },
  vite:config           {
  vite:config             find: /^\/?@vite\/client/,
  vite:config             replacement: '/@fs/C:/vite-preserve/.yarn/__virtual__/vite-virtual-dbc7c14500/4/Users/<USER>/AppData/Local/Yarn/Berry/cache/vite-npm-6.0.5-7387b23353-10c0.zip/node_modules/vite/dist/client/client.mjs'
  vite:config           }
  vite:config         ],
  vite:config         mainFields: [ 'browser', 'module', 'jsnext:main', 'jsnext' ],        
  vite:config         conditions: [ 'module', 'browser', 'development|production' ],       
  vite:config         enableBuiltinNoExternalCheck: false
  vite:config       },
  vite:config       keepProcessEnv: false,
  vite:config       consumer: 'client',
  vite:config       optimizeDeps: {
  vite:config         include: [],
  vite:config         exclude: [],
  vite:config         needsInterop: [],
  vite:config         extensions: [],
  vite:config         disabled: undefined,
  vite:config         holdUntilCrawlEnd: true,
  vite:config         force: false,
  vite:config         noDiscovery: false,
  vite:config         esbuildOptions: { preserveSymlinks: false }
  vite:config       },
  vite:config       dev: {
  vite:config         warmup: [],
  vite:config         sourcemap: { js: true },
  vite:config         sourcemapIgnoreList: [Function: isInNodeModules$1],
  vite:config         preTransformRequests: true,
  vite:config         createEnvironment: [Function: defaultCreateClientDevEnvironment],    
  vite:config         recoverable: true,
  vite:config         moduleRunnerTransform: false
  vite:config       },
  vite:config       build: {
  vite:config         target: [ 'es2020', 'edge88', 'firefox78', 'chrome87', 'safari14' ], 
  vite:config         polyfillModulePreload: true,
  vite:config         modulePreload: { polyfill: true },
  vite:config         outDir: 'dist',
  vite:config         assetsDir: 'assets',
  vite:config         assetsInlineLimit: 4096,
  vite:config         sourcemap: false,
  vite:config         terserOptions: {},
  vite:config         rollupOptions: {},
  vite:config         commonjsOptions: { include: [ /node_modules/ ], extensions: [ '.js', '.cjs' ] },
  vite:config         dynamicImportVarsOptions: { warnOnError: true, exclude: [ /node_modules/ ] },
  vite:config         write: true,
  vite:config         emptyOutDir: null,
  vite:config         copyPublicDir: true,
  vite:config         manifest: false,
  vite:config         lib: false,
  vite:config         ssrManifest: false,
  vite:config         ssrEmitAssets: false,
  vite:config         reportCompressedSize: true,
  vite:config         chunkSizeWarningLimit: 500,
  vite:config         watch: null,
  vite:config         cssCodeSplit: true,
  vite:config         minify: 'esbuild',
  vite:config         ssr: false,
  vite:config         emitAssets: true,
  vite:config         createEnvironment: [Function: createEnvironment],
  vite:config         cssTarget: [ 'es2020', 'edge88', 'firefox78', 'chrome87', 'safari14' ],
  vite:config         cssMinify: true
  vite:config       }
  vite:config     }
  vite:config   },
  vite:config   resolve: {
  vite:config     externalConditions: [ 'node' ],
  vite:config     extensions: [ '.mjs', '.js', '.ts', '.jsx', '.tsx', '.json' ],
  vite:config     dedupe: [],
  vite:config     noExternal: [],
  vite:config     external: [],
  vite:config     preserveSymlinks: false,
  vite:config     alias: [
  vite:config       {
  vite:config         find: /^\/?@vite\/env/,
  vite:config         replacement: '/@fs/C:/vite-preserve/.yarn/__virtual__/vite-virtual-dbc7c14500/4/Users/<USER>/AppData/Local/Yarn/Berry/cache/vite-npm-6.0.5-7387b23353-10c0.zip/node_modules/vite/dist/client/env.mjs'
  vite:config       },
  vite:config       {
  vite:config         find: /^\/?@vite\/client/,
  vite:config         replacement: '/@fs/C:/vite-preserve/.yarn/__virtual__/vite-virtual-dbc7c14500/4/Users/<USER>/AppData/Local/Yarn/Berry/cache/vite-npm-6.0.5-7387b23353-10c0.zip/node_modules/vite/dist/client/client.mjs'
  vite:config       }
  vite:config     ],
  vite:config     mainFields: [ 'module', 'jsnext:main', 'jsnext' ],
  vite:config     conditions: [ 'module', 'node', 'development|production' ],
  vite:config     enableBuiltinNoExternalCheck: false
  vite:config   },
  vite:config   configFile: 'C:/vite-preserve/vite.config.ts',   
  vite:config   configFileDependencies: [
  vite:config     'C:/vite-preserve/vitePluginApi.ts',
  vite:config     'C:/vite-preserve/vite.config.ts'
  vite:config   ],
  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:/vite-preserve',
  vite:config   base: '/',
  vite:config   decodedBase: '/',
  vite:config   rawBase: '/',
  vite:config   publicDir: 'C:/vite-preserve/public',
  vite:config   command: 'build',
  vite:config   mode: 'production',
  vite:config   isWorker: false,
  vite:config   mainConfig: null,
  vite:config   bundleChain: [],
  vite:config   isProduction: true,
  vite:config   css: {
  vite:config     transformer: 'postcss',
  vite:config     preprocessorMaxWorkers: 0,
  vite:config     devSourcemap: false,
  vite:config     lightningcss: undefined
  vite:config   },
  vite:config   json: { namedExports: true, stringify: 'auto' },
  vite:config   esbuild: { jsxDev: false },
  vite:config   server: {
  vite:config     port: 5173,
  vite:config     strictPort: false,
  vite:config     host: undefined,
  vite:config     https: undefined,
  vite:config     open: false,
  vite:config     proxy: undefined,
  vite:config     cors: true,
  vite:config     headers: {},
  vite:config     warmup: { clientFiles: [], ssrFiles: [] },
  vite:config     middlewareMode: false,
  vite:config     fs: {
  vite:config       strict: true,
  vite:config       deny: [ '.env', '.env.*', '*.{crt,pem}', '**/.git/**' ],
  vite:config       allow: [
  vite:config         'C:/vite-preserve',
  vite:config         'C:/Users/<USER>/AppData/Local/Yarn/Berry'
  vite:config       ]
  vite:config     },
  vite:config     preTransformRequests: true,
  vite:config     perEnvironmentStartEndDuringDev: false,
  vite:config     sourcemapIgnoreList: [Function: isInNodeModules$1]
  vite:config   },
  vite:config   builder: undefined,
  vite:config   preview: {
  vite:config     port: 4173,
  vite:config     strictPort: false,
  vite:config     host: undefined,
  vite:config     https: undefined,
  vite:config     open: false,
  vite:config     proxy: undefined,
  vite:config     cors: true,
  vite:config     headers: {}
  vite:config   },
  vite:config   envDir: 'C:/vite-preserve',
  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     warnOnce: [Function: warnOnce],
  vite:config     error: [Function: error],
  vite:config     clearScreen: [Function: clearScreen],
  vite:config     hasErrorLogged: [Function: hasErrorLogged]
  vite:config   },
  vite:config   packageCache: Map(1) {
  vite:config     'fnpd_C:/vite-preserve' => {
  vite:config       dir: 'C:/vite-preserve',
  vite:config       data: {
  vite:config         name: 'vite-preserve',
  vite:config         version: '1.0.0',
  vite:config         main: 'index.js',
  vite:config         license: 'MIT',
  vite:config         packageManager: '[email protected]',
  vite:config         scripts: { dev: 'vite', build: 'vite build', serve: 'vite preview' },
  vite:config         devDependencies: {
  vite:config           '@types/node': '^22.10.2',
  vite:config           '@yarnpkg/sdks': '^3.2.0',
  vite:config           typescript: '^5.7.2',
  vite:config           vite: '^6.0.5'
  vite:config         }
  vite:config       },
  vite:config       hasSideEffects: [Function: hasSideEffects],
  vite:config       setResolvedCache: [Function: setResolvedCache],
  vite:config       getResolvedCache: [Function: getResolvedCache]
  vite:config     },
  vite:config     set: [Function (anonymous)]
  vite:config   },
  vite:config   worker: { format: 'iife', plugins: '() => plugins', rollupOptions: {} },   
  vite:config   appType: 'spa',
  vite:config   experimental: { importGlobRestoreExtension: false, hmrPartialAccept: false },
  vite:config   future: undefined,
  vite:config   ssr: {
  vite:config     target: 'node',
  vite:config     optimizeDeps: { esbuildOptions: { preserveSymlinks: false } },
  vite:config     resolve: { conditions: undefined, externalConditions: undefined }        
  vite:config   },
  vite:config   optimizeDeps: {
  vite:config     include: [],
  vite:config     exclude: [],
  vite:config     needsInterop: [],
  vite:config     extensions: [],
  vite:config     disabled: undefined,
  vite:config     holdUntilCrawlEnd: true,
  vite:config     force: false,
  vite:config     noDiscovery: false,
  vite:config     esbuildOptions: { preserveSymlinks: false }
  vite:config   },
  vite:config   dev: {
  vite:config     warmup: [],
  vite:config     sourcemap: { js: true },
  vite:config     sourcemapIgnoreList: [Function: isInNodeModules$1],
  vite:config     preTransformRequests: false,
  vite:config     createEnvironment: [Function: defaultCreateDevEnvironment],
  vite:config     recoverable: false,
  vite:config     moduleRunnerTransform: false
  vite:config   },
  vite:config   getSortedPlugins: [Function: getSortedPlugins],
  vite:config   getSortedPluginHooks: [Function: getSortedPluginHooks],
  vite:config   createResolver: [Function: createResolver],
  vite:config   fsDenyGlob: [Function: arrayMatcher],
  vite:config   safeModulePaths: Set(0) {}
  vite:config } +537ms
vite v6.0.5 building for production...
entryFilepathFull:  {
  'user/[id]/(post)': 'C:/vite-preserve/server/api/user/[id]/(post).ts'
}
(node:35096) ExperimentalWarning: globSync is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
  vite:config using resolved config: {
  vite:config   configFile: undefined,
  vite:config   build: {
  vite:config     target: 'esnext',
  vite:config     polyfillModulePreload: true,
  vite:config     modulePreload: { polyfill: true },
  vite:config     outDir: 'dist',
  vite:config     assetsDir: 'assets',
  vite:config     assetsInlineLimit: 4096,
  vite:config     sourcemap: false,
  vite:config     terserOptions: {},
  vite:config     rollupOptions: {
  vite:config       input: {
  vite:config         'user/[id]/(post)': 'C:/vite-preserve/server/api/user/[id]/(post).ts'
  vite:config       },
  vite:config       output: {
  vite:config         dir: 'C:\\vite-preserve\\dist\\server\\api',
  vite:config         format: 'esm',
  vite:config         entryFileNames: '[name].mjs'
  vite:config       }
  vite:config     },
  vite:config     commonjsOptions: { include: [ /node_modules/ ], extensions: [ '.js', '.cjs' ] },
  vite:config     dynamicImportVarsOptions: { warnOnError: true, exclude: [ /node_modules/ ] },
  vite:config     write: true,
  vite:config     emptyOutDir: null,
  vite:config     copyPublicDir: true,
  vite:config     manifest: false,
  vite:config     lib: false,
  vite:config     ssrManifest: false,
  vite:config     ssrEmitAssets: false,
  vite:config     reportCompressedSize: true,
  vite:config     chunkSizeWarningLimit: 500,
  vite:config     watch: null,
  vite:config     cssCodeSplit: true,
  vite:config     minify: false,
  vite:config     ssr: true,
  vite:config     emitAssets: false,
  vite:config     createEnvironment: [Function: createEnvironment],
  vite:config     cssTarget: 'esnext',
  vite:config     cssMinify: 'esbuild'
  vite:config   },
  vite:config   environments: {
  vite:config     client: {
  vite:config       define: undefined,
  vite:config       resolve: {
  vite:config         externalConditions: [ 'node' ],
  vite:config         extensions: [ '.mjs', '.js', '.ts', '.jsx', '.tsx', '.json' ],       
  vite:config         dedupe: [],
  vite:config         noExternal: [],
  vite:config         external: [],
  vite:config         preserveSymlinks: false,
  vite:config         alias: [
  vite:config           {
  vite:config             find: /^\/?@vite\/env/,
  vite:config             replacement: '/@fs/C:/vite-preserve/.yarn/__virtual__/vite-virtual-dbc7c14500/4/Users/<USER>/AppData/Local/Yarn/Berry/cache/vite-npm-6.0.5-7387b23353-10c0.zip/node_modules/vite/dist/client/env.mjs'
  vite:config           },
  vite:config           {
  vite:config             find: /^\/?@vite\/client/,
  vite:config             replacement: '/@fs/C:/vite-preserve/.yarn/__virtual__/vite-virtual-dbc7c14500/4/Users/<USER>/AppData/Local/Yarn/Berry/cache/vite-npm-6.0.5-7387b23353-10c0.zip/node_modules/vite/dist/client/client.mjs'
  vite:config           }
  vite:config         ],
  vite:config         mainFields: [ 'browser', 'module', 'jsnext:main', 'jsnext' ],        
  vite:config         conditions: [ 'module', 'browser', 'development|production' ],       
  vite:config         enableBuiltinNoExternalCheck: false
  vite:config       },
  vite:config       keepProcessEnv: false,
  vite:config       consumer: 'client',
  vite:config       optimizeDeps: {
  vite:config         include: [],
  vite:config         exclude: [],
  vite:config         needsInterop: [],
  vite:config         extensions: [],
  vite:config         disabled: undefined,
  vite:config         holdUntilCrawlEnd: true,
  vite:config         force: false,
  vite:config         noDiscovery: false,
  vite:config         esbuildOptions: { preserveSymlinks: false }
  vite:config       },
  vite:config       dev: {
  vite:config         warmup: [],
  vite:config         sourcemap: { js: true },
  vite:config         sourcemapIgnoreList: [Function: isInNodeModules$1],
  vite:config         preTransformRequests: true,
  vite:config         createEnvironment: [Function: defaultCreateClientDevEnvironment],    
  vite:config         recoverable: true,
  vite:config         moduleRunnerTransform: false
  vite:config       },
  vite:config       build: {
  vite:config         target: 'esnext',
  vite:config         polyfillModulePreload: true,
  vite:config         modulePreload: { polyfill: true },
  vite:config         outDir: 'dist',
  vite:config         assetsDir: 'assets',
  vite:config         assetsInlineLimit: 4096,
  vite:config         sourcemap: false,
  vite:config         terserOptions: {},
  vite:config         rollupOptions: {
  vite:config           input: {
  vite:config             'user/[id]/(post)': 'C:/vite-preserve/server/api/user/[id]/(post).ts'
  vite:config           },
  vite:config           output: {
  vite:config             dir: 'C:\\vite-preserve\\dist\\server\\api',
  vite:config             format: 'esm',
  vite:config             entryFileNames: '[name].mjs'
  vite:config           }
  vite:config         },
  vite:config         commonjsOptions: { include: [ /node_modules/ ], extensions: [ '.js', '.cjs' ] },
  vite:config         dynamicImportVarsOptions: { warnOnError: true, exclude: [ /node_modules/ ] },
  vite:config         write: true,
  vite:config         emptyOutDir: null,
  vite:config         copyPublicDir: true,
  vite:config         manifest: false,
  vite:config         lib: false,
  vite:config         ssrManifest: false,
  vite:config         ssrEmitAssets: false,
  vite:config         reportCompressedSize: true,
  vite:config         chunkSizeWarningLimit: 500,
  vite:config         watch: null,
  vite:config         cssCodeSplit: true,
  vite:config         minify: 'esbuild',
  vite:config         ssr: true,
  vite:config         emitAssets: true,
  vite:config         createEnvironment: [Function: createEnvironment],
  vite:config         cssTarget: 'esnext',
  vite:config         cssMinify: true
  vite:config       }
  vite:config     },
  vite:config     ssr: {
  vite:config       define: undefined,
  vite:config       resolve: {
  vite:config         externalConditions: [ 'node' ],
  vite:config         extensions: [ '.mjs', '.js', '.ts', '.jsx', '.tsx', '.json' ],       
  vite:config         dedupe: [],
  vite:config         noExternal: [],
  vite:config         external: [],
  vite:config         preserveSymlinks: false,
  vite:config         alias: [
  vite:config           {
  vite:config             find: /^\/?@vite\/env/,
  vite:config             replacement: '/@fs/C:/vite-preserve/.yarn/__virtual__/vite-virtual-dbc7c14500/4/Users/<USER>/AppData/Local/Yarn/Berry/cache/vite-npm-6.0.5-7387b23353-10c0.zip/node_modules/vite/dist/client/env.mjs'
  vite:config           },
  vite:config           {
  vite:config             find: /^\/?@vite\/client/,
  vite:config             replacement: '/@fs/C:/vite-preserve/.yarn/__virtual__/vite-virtual-dbc7c14500/4/Users/<USER>/AppData/Local/Yarn/Berry/cache/vite-npm-6.0.5-7387b23353-10c0.zip/node_modules/vite/dist/client/client.mjs'
  vite:config           }
  vite:config         ],
  vite:config         mainFields: [ 'module', 'jsnext:main', 'jsnext' ],
  vite:config         conditions: [ 'module', 'node', 'development|production' ],
  vite:config         enableBuiltinNoExternalCheck: false
  vite:config       },
  vite:config       keepProcessEnv: true,
  vite:config       consumer: 'server',
  vite:config       optimizeDeps: {
  vite:config         include: [],
  vite:config         exclude: [],
  vite:config         needsInterop: [],
  vite:config         extensions: [],
  vite:config         disabled: undefined,
  vite:config         holdUntilCrawlEnd: true,
  vite:config         force: false,
  vite:config         noDiscovery: true,
  vite:config         esbuildOptions: { preserveSymlinks: false }
  vite:config       },
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  vite:config         chunkSizeWarningLimit: 500,
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  vite:config   },
  vite:config   resolve: {
  vite:config     externalConditions: [ 'node' ],
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  vite:config       {
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  vite:config       {
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  vite:config         build: {
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  vite:config   css: {
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  vite:config     lightningcss: undefined
  vite:config   },
  vite:config   json: { namedExports: true, stringify: 'auto' },
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  vite:config   server: {
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  vite:config     strictPort: false,
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  vite:config     host: undefined,
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  vite:config     headers: {}
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  vite:config   envDir: 'C:/vite-preserve',
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  vite:config   assetsInclude: [Function: assetsInclude],
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  vite:config   packageCache: Map(1) {
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  vite:config   worker: { format: 'iife', plugins: '() => plugins', rollupOptions: {} },   
  vite:config   appType: 'spa',
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  vite:config       include: [],
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  vite:config   dev: {
  vite:config     warmup: [],
  vite:config     createEnvironment: [Function: defaultCreateDevEnvironment],
  vite:config     recoverable: false,
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  vite:config   getSortedPlugins: [Function: getSortedPlugins],
  vite:config   getSortedPluginHooks: [Function: getSortedPluginHooks],
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vite v6.0.5 building SSR bundle for production...
✓ 1 modules transformed.
dist/server/api/user/_id_/(post).mjs  0.04 kB
✓ built in 29ms
✓ 0 modules transformed.
x Build failed in 622ms
error during build:
Could not resolve entry module "index.html".
    at getRollupError (file:///C:/Users/<USER>/AppData/Local/Yarn/Berry/cache/rollup-npm-4.29.0-891a59f877-10c0.zip/node_modules/rollup/dist/es/shared/parseAst.js:396:41)
    at error (file:///C:/Users/<USER>/AppData/Local/Yarn/Berry/cache/rollup-npm-4.29.0-891a59f877-10c0.zip/node_modules/rollup/dist/es/shared/parseAst.js:392:42)
    at ModuleLoader.loadEntryModule (file:///C:/Users/<USER>/AppData/Local/Yarn/Berry/cache/rollup-npm-4.29.0-891a59f877-10c0.zip/node_modules/rollup/dist/es/shared/node-entry.js:20161:20)
    at async Promise.all (index 0)

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• 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 vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[sapphi-red]

Rollup escapes [/] by default.
https://github.com/rollup/rollup/blob/5d3777803404c67ce14c62b8b05d6e26e46856f5/src/utils/sanitizeFileName.ts#L3
You can set build.rollupOptions.output.sanitizeFileName to configure that.