Tracing: allow opt-in flag to send build traces to url

packages/next/src/bin/next.ts

@@ -124,6 +124,10 @@ program
     '--experimental-debug-memory-usage',
     'Enables memory profiling features to debug memory consumption.'
   )
+  .option(
+    '--experimental-upload-trace, <traceUrl>',
+    'Reports a subset of the debugging trace to a remote HTTP URL. Includes sensitive data.'
+  )
   .action((directory, options) =>
     // ensure process exits after build completes so open handles/connections
     // don't cause process to hang

packages/next/src/build/index.ts

@@ -186,6 +186,7 @@ import { createProgress } from './progress'
 import { traceMemoryUsage } from '../lib/memory/trace'
 import { generateEncryptionKeyBase64 } from '../server/app-render/encryption-utils'
 import type { DeepReadonly } from '../shared/lib/deep-readonly'
+import uploadTrace from '../trace/upload-trace'
 
 interface ExperimentalBypassForInfo {
   experimentalBypassFor?: RouteHas[]
@@ -703,11 +704,13 @@ export default async function build(
   noMangling = false,
   appDirOnly = false,
   turboNextBuild = false,
-  experimentalBuildMode: 'default' | 'compile' | 'generate'
+  experimentalBuildMode: 'default' | 'compile' | 'generate',
+  traceUploadUrl: string | undefined
 ): Promise<void> {
   const isCompileMode = experimentalBuildMode === 'compile'
   const isGenerateMode = experimentalBuildMode === 'generate'
 
+  let loadedConfig: NextConfigComplete | undefined
   try {
     const nextBuildSpan = trace('next-build', undefined, {
       buildMode: experimentalBuildMode,
@@ -741,6 +744,7 @@ export default async function build(
             turborepoAccessTraceResult
           )
         )
+      loadedConfig = config
 
       process.env.NEXT_DEPLOYMENT_ID = config.deploymentId || ''
       NextBuildContext.config = config
@@ -3442,5 +3446,15 @@ export default async function build(
     await flushAllTraces()
     teardownTraceSubscriber()
     teardownHeapProfiler()
+
+    if (traceUploadUrl && loadedConfig) {
+      uploadTrace({
+        traceUploadUrl,
+        mode: 'build',
+        projectDir: dir,
+        distDir: loadedConfig.distDir,
+        sync: true,
+      })
+    }
   }
 }

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

@@ -20,6 +20,7 @@ type NextBuildOptions = {
   experimentalAppOnly?: boolean
   experimentalTurbo?: boolean
   experimentalBuildMode: 'default' | 'compile' | 'generate'
+  experimentalUploadTrace?: string
 }
 
 const nextBuild = (options: NextBuildOptions, directory?: string) => {
@@ -35,8 +36,14 @@ const nextBuild = (options: NextBuildOptions, directory?: string) => {
     experimentalAppOnly,
     experimentalTurbo,
     experimentalBuildMode,
+    experimentalUploadTrace,
   } = options
 
+  let traceUploadUrl: string | undefined
+  if (experimentalUploadTrace && !process.env.NEXT_TRACE_UPLOAD_DISABLED) {
+    traceUploadUrl = experimentalUploadTrace
+  }
+
   if (!lint) {
     warn('Linting is disabled.')
   }
@@ -77,7 +84,8 @@ const nextBuild = (options: NextBuildOptions, directory?: string) => {
     !mangling,
     experimentalAppOnly,
     !!process.env.TURBOPACK,
-    experimentalBuildMode
+    experimentalBuildMode,
+    traceUploadUrl
   )
     .catch((err) => {
       if (experimentalDebugMemoryUsage) {

packages/next/src/trace/trace-uploader.ts

@@ -12,7 +12,7 @@ import { Telemetry } from '../telemetry/storage'
 // Predefined set of the event names to be included in the trace.
 // If the trace span's name matches to one of the event names in the set,
 // it'll up uploaded to the trace server.
-const EVENT_FILTER = new Set([
+const DEV_EVENT_ALLOW = new Set([
   'client-hmr-latency',
   'hot-reloader',
   'webpack-invalid-client',
@@ -24,6 +24,35 @@ const EVENT_FILTER = new Set([
   'server-restart-close-to-memory-threshold',
 ])
 
+const BUILD_EVENT_ALLOW = new Set([
+  'next-build',
+  'webpack-compilation',
+  'run-webpack-compiler',
+  'create-entrypoints',
+  'server',
+  'next-trace-entrypoint-plugin',
+  'make',
+  'add-entry',
+  'seal',
+  'chunk-graph',
+  'optimize-modules',
+  'optimize-chunks',
+  'optimize',
+  'optimize-tree',
+  'optimize-chunk-modules',
+  'module-hash',
+  'emit',
+  'client',
+  'static-check',
+  'check-page',
+  'node-file-trace-build',
+  'static-generation',
+  'next-export',
+  'export-page',
+  'verify-typescript-setup',
+  'verify-and-lint',
+])
+
 const {
   NEXT_TRACE_UPLOAD_DEBUG,
   // An external env to allow to upload full trace without picking up the relavant spans.
@@ -107,7 +136,9 @@ interface TraceMetadata {
         // Always include root spans
         event.parentId === undefined ||
         shouldUploadFullTrace ||
-        EVENT_FILTER.has(event.name)
+        (mode === 'dev'
+          ? DEV_EVENT_ALLOW.has(event.name)
+          : BUILD_EVENT_ALLOW.has(event.name))
       ) {
         let trace = traces.get(event.traceId)
         if (trace === undefined) {

packages/next/src/trace/upload-trace.ts

@@ -6,7 +6,7 @@ export default function uploadTrace({
   sync,
 }: {
   traceUploadUrl: string
-  mode: 'dev'
+  mode: 'dev' | 'build'
   projectDir: string
   distDir: string
   sync?: boolean