Use separate workers for webpackBuildWorker

packages/next/src/build/build-context.ts

@@ -5,13 +5,30 @@ import type { __ApiPreviewProps } from '../server/api-utils'
 import type { NextConfigComplete } from '../server/config-shared'
 import type { Span } from '../trace'
 import type getBaseWebpackConfig from './webpack-config'
+import { PagesManifest } from './webpack/plugins/pages-manifest-plugin'
 import type { TelemetryPlugin } from './webpack/plugins/telemetry-plugin'
 
 // a global object to store context for the current build
 // this is used to pass data between different steps of the build without having
 // to pass it through function arguments.
 // Not exhaustive, but should be extended to as needed whilst refactoring
 export const NextBuildContext: Partial<{
+  compilerIdx?: number
+  serializedFlightMaps?: {
+    injectedClientEntries?: any
+    serverModuleIds?: any
+    edgeServerModuleIds?: any
+    asyncClientModules?: any
+    serverActions?: any
+    serverCSSManifest?: any
+    edgeServerCSSManifest?: any
+  }
+  serializedPagesManifestEntries: {
+    edgeServerPages?: PagesManifest
+    nodeServerPages?: PagesManifest
+    edgeServerAppPaths?: PagesManifest
+    nodeServerAppPaths?: PagesManifest
+  }
   // core fields
   dir: string
   buildId: string

packages/next/src/build/index.ts

@@ -1068,7 +1068,9 @@ export default async function build(
             if (filesTracedFromEntries.length) {
               // The turbo trace doesn't provide the traced file type and reason at present
               // let's write the traced files into the first [entry].nft.json
+              // @ts-expect-error types
               const [[, entryName]] = Array.from(entryNameMap.entries()).filter(
+                // @ts-expect-error types
                 ([k]) => k.startsWith(turbotraceContextAppDir)
               )
               const traceOutputPath = path.join(
@@ -1085,7 +1087,7 @@ export default async function build(
           }
           if (chunksTrace) {
             const { action, outputPath } = chunksTrace
-            action.input = action.input.filter((f) => {
+            action.input = action.input.filter((f: any) => {
               const outputPagesPath = path.join(outputPath, '..', 'pages')
               return (
                 !f.startsWith(outputPagesPath) ||

packages/next/src/build/swc/index.ts

@@ -16,6 +16,13 @@ const ArchName = arch()
 const PlatformName = platform()
 const triples = platformArchTriples[PlatformName][ArchName] || []
 
+const infoLog = (...args: any[]) => {
+  if (process.env.NEXT_PRIVATE_BUILD_WORKER) {
+    return
+  }
+  Log.info(...args)
+}
+
 // Allow to specify an absolute path to the custom turbopack binary to load.
 // If one of env variables is set, `loadNative` will try to use any turbo-* interfaces from specified
 // binary instead. This will not affect existing swc's transform, or other interfaces. This is thin,
@@ -213,7 +220,7 @@ async function loadWasm(importPath = '') {
       if (pkg === '@next/swc-wasm-web') {
         bindings = await bindings.default()
       }
-      Log.info('Using wasm build of next-swc')
+      infoLog('Using wasm build of next-swc')
 
       // Note wasm binary does not support async intefaces yet, all async
       // interface coereces to sync interfaces.
@@ -292,7 +299,7 @@ function loadNative(isCustomTurbopack = false) {
   for (const triple of triples) {
     try {
       bindings = require(`@next/swc/native/next-swc.${triple.platformArchABI}.node`)
-      Log.info('Using locally built binary of @next/swc')
+      infoLog('Using locally built binary of @next/swc')
       break
     } catch (e) {}
   }