code · pull · Jan 21, 2026 · Jan 21, 2026 · Jan 21, 2026 · Jan 21, 2026
diff --git a/.github/workflows/integration_tests_reusable.yml b/.github/workflows/integration_tests_reusable.yml
@@ -94,6 +94,7 @@ jobs:
         export NEXT_TEST_MODE=${{
           inputs.test_type == 'development' && 'dev' || 'start'
         }}
+        export NEXT_TEST_EMIT_ALL_OUTPUT=1
 
         ${{ inputs.run_before_test }}
 
@@ -129,6 +130,7 @@ jobs:
             'TURBOPACK_DEV=1' ||
             'TURBOPACK_BUILD=1'
         }}
+        export NEXT_TEST_EMIT_ALL_OUTPUT=1
 
         ${{ inputs.run_before_test }}
 

diff --git a/Cargo.lock b/Cargo.lock
diff --git a/lerna.json b/lerna.json
@@ -15,5 +15,5 @@
       "registry": "https://registry.npmjs.org/"
     }
   },
-  "version": "16.1.1-canary.36"
+  "version": "16.2.0-canary.0"
 }
diff --git a/packages/create-next-app/package.json b/packages/create-next-app/package.json
@@ -1,6 +1,6 @@
 {
   "name": "create-next-app",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "keywords": [
     "react",
     "next",

diff --git a/packages/eslint-config-next/package.json b/packages/eslint-config-next/package.json
@@ -1,6 +1,6 @@
 {
   "name": "eslint-config-next",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "description": "ESLint configuration used by Next.js.",
   "license": "MIT",
   "repository": {
@@ -12,7 +12,7 @@
     "dist"
   ],
   "dependencies": {
-    "@next/eslint-plugin-next": "16.1.1-canary.36",
+    "@next/eslint-plugin-next": "16.2.0-canary.0",
     "eslint-import-resolver-node": "^0.3.6",
     "eslint-import-resolver-typescript": "^3.5.2",
     "eslint-plugin-import": "^2.32.0",

diff --git a/packages/eslint-plugin-internal/package.json b/packages/eslint-plugin-internal/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@next/eslint-plugin-internal",
   "private": true,
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "description": "ESLint plugin for working on Next.js.",
   "exports": {
     ".": "./src/eslint-plugin-internal.js"

diff --git a/packages/eslint-plugin-next/package.json b/packages/eslint-plugin-next/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/eslint-plugin-next",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "description": "ESLint plugin for Next.js.",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

diff --git a/packages/font/package.json b/packages/font/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@next/font",
   "private": true,
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "repository": {
     "url": "vercel/next.js",
     "directory": "packages/font"

diff --git a/packages/next-bundle-analyzer/package.json b/packages/next-bundle-analyzer/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/bundle-analyzer",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "main": "index.js",
   "types": "index.d.ts",
   "license": "MIT",

diff --git a/packages/next-codemod/package.json b/packages/next-codemod/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/codemod",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "license": "MIT",
   "repository": {
     "type": "git",

diff --git a/packages/next-env/package.json b/packages/next-env/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/env",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "keywords": [
     "react",
     "next",

diff --git a/packages/next-mdx/package.json b/packages/next-mdx/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/mdx",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "main": "index.js",
   "license": "MIT",
   "repository": {

diff --git a/packages/next-plugin-storybook/package.json b/packages/next-plugin-storybook/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/plugin-storybook",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "repository": {
     "url": "vercel/next.js",
     "directory": "packages/next-plugin-storybook"

diff --git a/packages/next-polyfill-module/package.json b/packages/next-polyfill-module/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/polyfill-module",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "description": "A standard library polyfill for ES Modules supporting browsers (Edge 16+, Firefox 60+, Chrome 61+, Safari 10.1+)",
   "main": "dist/polyfill-module.js",
   "license": "MIT",

diff --git a/packages/next-polyfill-nomodule/package.json b/packages/next-polyfill-nomodule/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/polyfill-nomodule",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "description": "A polyfill for non-dead, nomodule browsers.",
   "main": "dist/polyfill-nomodule.js",
   "license": "MIT",

diff --git a/packages/next-routing/package.json b/packages/next-routing/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/routing",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "keywords": [
     "react",
     "next",

diff --git a/packages/next-rspack/package.json b/packages/next-rspack/package.json
@@ -1,6 +1,6 @@
 {
   "name": "next-rspack",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "repository": {
     "url": "vercel/next.js",
     "directory": "packages/next-rspack"

diff --git a/packages/next-swc/package.json b/packages/next-swc/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/swc",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "private": true,
   "files": [
     "native/"

diff --git a/packages/next/errors.json b/packages/next/errors.json
@@ -979,5 +979,6 @@
   "978": "Next.js has blocked a javascript: URL as a security precaution.",
   "979": "invariant: expected %s bytes of postponed state but only received %s bytes",
   "980": "Failed to load client middleware manifest",
-  "981": "resolvedPathname must be set in request metadata"
+  "981": "resolvedPathname must be set in request metadata",
+  "982": "`serializeResumeDataCache` should not be called in edge runtime."
 }
diff --git a/packages/next/package.json b/packages/next/package.json
@@ -1,6 +1,6 @@
 {
   "name": "next",
-  "version": "16.1.1-canary.36",
+  "version": "16.2.0-canary.0",
   "description": "The React Framework",
   "main": "./dist/server/next.js",
   "license": "MIT",
@@ -97,7 +97,7 @@
     ]
   },
   "dependencies": {
-    "@next/env": "16.1.1-canary.36",
+    "@next/env": "16.2.0-canary.0",
     "@swc/helpers": "0.5.15",
     "baseline-browser-mapping": "^2.8.3",
     "caniuse-lite": "^1.0.30001579",
@@ -162,11 +162,11 @@
     "@modelcontextprotocol/sdk": "1.18.1",
     "@mswjs/interceptors": "0.23.0",
     "@napi-rs/triples": "1.2.0",
-    "@next/font": "16.1.1-canary.36",
-    "@next/polyfill-module": "16.1.1-canary.36",
-    "@next/polyfill-nomodule": "16.1.1-canary.36",
-    "@next/react-refresh-utils": "16.1.1-canary.36",
-    "@next/swc": "16.1.1-canary.36",
+    "@next/font": "16.2.0-canary.0",
+    "@next/polyfill-module": "16.2.0-canary.0",
+    "@next/polyfill-nomodule": "16.2.0-canary.0",
+    "@next/react-refresh-utils": "16.2.0-canary.0",
+    "@next/swc": "16.2.0-canary.0",
     "@opentelemetry/api": "1.6.0",
     "@playwright/test": "1.51.1",
     "@rspack/core": "1.6.7",

diff --git a/packages/next/src/export/index.ts b/packages/next/src/export/index.ts
@@ -69,11 +69,125 @@ import type { ActionManifest } from '../build/webpack/plugins/flight-client-entr
 import { extractInfoFromServerReferenceId } from '../shared/lib/server-reference-info'
 import { convertSegmentPathToStaticExportFilename } from '../shared/lib/segment-cache/segment-value-encoding'
 import { getNextBuildDebuggerPortOffset } from '../lib/worker'
+import { getParams } from './helpers/get-params'
+import { isDynamicRoute } from '../shared/lib/router/utils/is-dynamic'
+import { normalizeAppPath } from '../shared/lib/router/utils/app-paths'
+import type { Params } from '../server/request/params'
 
 export class ExportError extends Error {
   code = 'NEXT_EXPORT_ERROR'
 }
 
+/**
+ * Picks an RDC seed by matching on the params that are
+ * already known, so fallback shells use a seed that has already
+ * computed those known params.
+ */
+function buildRDCCacheByPage(
+  results: ExportPagesResult,
+  finalPhaseExportPaths: ExportPathEntry[]
+): Record<string, string> {
+  const renderResumeDataCachesByPage: Record<string, string> = {}
+  const seedCandidatesByPage = new Map<
+    string,
+    Array<{ path: string; renderResumeDataCache: string }>
+  >()
+
+  for (const { page, path, result } of results) {
+    if (!result) {
+      continue
+    }
+
+    if ('renderResumeDataCache' in result && result.renderResumeDataCache) {
+      // Collect all RDC seeds for this page so we can pick the best match
+      // for each fallback shell later (e.g. locale-specific variants).
+      const candidates = seedCandidatesByPage.get(page) ?? []
+      candidates.push({
+        path,
+        renderResumeDataCache: result.renderResumeDataCache,
+      })
+      seedCandidatesByPage.set(page, candidates)
+      // Remove the RDC string from the result so that it can be garbage
+      // collected, when there are more results for the same page.
+      result.renderResumeDataCache = undefined
+    }
+  }
+
+  const getKnownParamsKey = (
+    normalizedPage: string,
+    path: string,
+    fallbackParamNames: Set<string>
+  ): string | null => {
+    let params: Params
+    try {
+      params = getParams(normalizedPage, path)
+    } catch {
+      return null
+    }
+
+    // Only keep params that are known, then sort
+    // for a stable key so we can match a compatible seed.
+    const entries = Object.entries(params).filter(
+      ([key]) => !fallbackParamNames.has(key)
+    )
+
+    entries.sort(([a], [b]) => (a < b ? -1 : a > b ? 1 : 0))
+    return JSON.stringify(entries)
+  }
+
+  for (const exportPath of finalPhaseExportPaths) {
+    const { page, path, _fallbackRouteParams = [] } = exportPath
+    if (!isDynamicRoute(page)) {
+      continue
+    }
+
+    // Normalize app pages before param matching.
+    const normalizedPage = normalizeAppPath(page)
+    const pageKey = page !== path ? `${page}: ${path}` : path
+    const fallbackParamNames = new Set(
+      _fallbackRouteParams.map((param) => param.paramName)
+    )
+    // Build a key from the known params for this fallback shell so we can
+    // select a seed from a compatible prerendered route.
+    const targetKey = getKnownParamsKey(
+      normalizedPage,
+      path,
+      fallbackParamNames
+    )
+
+    if (!targetKey) {
+      continue
+    }
+
+    const candidates = seedCandidatesByPage.get(page)
+
+    // No suitable candidates, so there's no RDC seed to select
+    if (!candidates || candidates.length === 0) {
+      continue
+    }
+
+    let selected: string | null = null
+    for (const candidate of candidates) {
+      // Pick the seed whose known params match this fallback shell.
+      const candidateKey = getKnownParamsKey(
+        normalizedPage,
+        candidate.path,
+        fallbackParamNames
+      )
+      if (candidateKey === targetKey) {
+        selected = candidate.renderResumeDataCache
+        break
+      }
+    }
+
+    if (selected) {
+      renderResumeDataCachesByPage[pageKey] = selected
+    }
+  }
+
+  return renderResumeDataCachesByPage
+}
+
 async function exportAppImpl(
   dir: string,
   options: Readonly<ExportAppOptions>,
@@ -664,23 +778,10 @@ async function exportAppImpl(
     results = await exportPagesInBatches(worker, initialPhaseExportPaths)
 
     if (finalPhaseExportPaths.length > 0) {
-      const renderResumeDataCachesByPage: Record<string, string> = {}
-
-      for (const { page, result } of results) {
-        if (!result) {
-          continue
-        }
-
-        if ('renderResumeDataCache' in result && result.renderResumeDataCache) {
-          // The last RDC for each page is used. We only need one. It should have
-          // all the entries that the fallback shell also needs. We don't need to
-          // merge them per page.
-          renderResumeDataCachesByPage[page] = result.renderResumeDataCache
-          // Remove the RDC string from the result so that it can be garbage
-          // collected, when there are more results for the same page.
-          result.renderResumeDataCache = undefined
-        }
-      }
+      const renderResumeDataCachesByPage = buildRDCCacheByPage(
+        results,
+        finalPhaseExportPaths
+      )
 
       const finalPhaseResults = await exportPagesInBatches(
         worker,

diff --git a/packages/next/src/export/worker.ts b/packages/next/src/export/worker.ts
@@ -388,9 +388,9 @@ export async function exportPages(
       // Also tests for `inspect-brk`
       process.env.NODE_OPTIONS?.includes('--inspect')
 
-    const renderResumeDataCache = renderResumeDataCachesByPage[page]
+    const renderResumeDataCache = renderResumeDataCachesByPage[pageKey]
       ? createRenderResumeDataCache(
-          renderResumeDataCachesByPage[page],
+          renderResumeDataCachesByPage[pageKey],
           renderOpts.experimental.maxPostponedStateSizeBytes
         )
       : undefined