[pull] canary from vercel:canary

.github/workflows/build_reusable.yml

@@ -317,9 +317,10 @@ jobs:
         timeout-minutes: ${{ inputs.timeout_minutes }}
 
       # This file messes up the tests because it influences the build root autodetection.
+      # Jest has a global cache, so PRs that poison the cache can bring down CI
       - name: Clean up stray files
         if: ${{ always() }}
-        run: rm -f /tmp/package-lock.json
+        run: rm -f /tmp/package-lock.json .jest-cache
 
       - name: Upload artifact
         uses: actions/upload-artifact@v4

.github/workflows/test_e2e_deploy_release.yml

@@ -19,6 +19,14 @@ on:
         description: Override the proxy address to use for the test
         default: ''
         type: string
+      deployScriptPath:
+        description: Custom deploy script path (NEXT_TEST_DEPLOY_SCRIPT_PATH)
+        default: ''
+        type: string
+      deployLogsScriptPath:
+        description: Custom deploy logs script path (NEXT_TEST_DEPLOY_LOGS_SCRIPT_PATH)
+        default: ''
+        type: string
 
 env:
   DD_ENV: 'ci'
@@ -84,6 +92,8 @@ jobs:
         NEXT_EXTERNAL_TESTS_FILTERS="test/deploy-tests-manifest.json" \
         NEXT_TEST_VERSION="${{ github.event.inputs.nextVersion || needs.setup.outputs.next-version || 'canary' }}" \
         VERCEL_CLI_VERSION="${{ github.event.inputs.vercelCliVersion || 'vercel@latest' }}" \
+        NEXT_TEST_DEPLOY_SCRIPT_PATH="${{ github.event.inputs.deployScriptPath || '' }}" \
+        NEXT_TEST_DEPLOY_LOGS_SCRIPT_PATH="${{ github.event.inputs.deployLogsScriptPath || '' }}" \
         node run-tests.js --timings -g ${{ matrix.group }} -c 2 --type e2e
       skipNativeBuild: 'yes'
       skipNativeInstall: 'no'
@@ -95,6 +105,7 @@ jobs:
   test-deploy-adapter:
     name: Run Deploy Adapter Tests
     needs: setup
+    if: ${{ github.event.inputs.deployScriptPath == '' }}
     uses: ./.github/workflows/build_reusable.yml
     secrets: inherit
     strategy:

.gitignore

@@ -60,6 +60,7 @@ test-timings.json
 *.tsbuildinfo
 .swc/
 .turbo
+.jest-cache/
 
 # Storybook
 *storybook.log

crates/next-api/src/project.rs

@@ -779,9 +779,9 @@ pub struct Project {
     /// E.g. `.next`
     dist_dir: RcStr,
 
-    /// The root directory of the distDir. Generally the same as `distDir` but when
-    /// `isolatedDevBuild` is true it is the parent directory of `distDir`.  This is used to
-    /// ensure that the bundler doesn't traverse into the output directory.
+    /// The root directory of the distDir. In development mode, this is the parent directory of
+    /// `distDir` since development builds use `{distDir}/dev`. This is used to ensure that the
+    /// bundler doesn't traverse into the output directory.
     dist_dir_root: RcStr,
 
     /// Filesystem watcher options.

crates/next-core/src/next_client/context.rs

@@ -488,7 +488,8 @@ pub async fn get_client_chunking_context(
     .module_id_strategy(module_id_strategy.to_resolved().await?)
     .debug_ids(*debug_ids.await?)
     .should_use_absolute_url_references(*should_use_absolute_url_references.await?)
-    .nested_async_availability(*nested_async_chunking.await?);
+    .nested_async_availability(*nested_async_chunking.await?)
+    .worker_forwarded_globals(vec![rcstr!("NEXT_DEPLOYMENT_ID")]);
 
     if next_mode.is_development() {
         builder = builder

crates/next-core/src/next_edge/context.rs

@@ -263,7 +263,8 @@ pub async fn get_edge_chunking_context_with_client_assets(
     .module_id_strategy(module_id_strategy.to_resolved().await?)
     .export_usage(*export_usage.await?)
     .unused_references(unused_references.to_resolved().await?)
-    .nested_async_availability(*nested_async_chunking.await?);
+    .nested_async_availability(*nested_async_chunking.await?)
+    .worker_forwarded_globals(vec![rcstr!("NEXT_DEPLOYMENT_ID")]);
 
     if !next_mode.is_development() {
         builder = builder
@@ -346,7 +347,8 @@ pub async fn get_edge_chunking_context(
     .module_id_strategy(module_id_strategy.to_resolved().await?)
     .export_usage(*export_usage.await?)
     .unused_references(unused_references.to_resolved().await?)
-    .nested_async_availability(*nested_async_chunking.await?);
+    .nested_async_availability(*nested_async_chunking.await?)
+    .worker_forwarded_globals(vec![rcstr!("NEXT_DEPLOYMENT_ID")]);
 
     if !next_mode.is_development() {
         builder = builder

docs/01-app/02-guides/local-development.mdx

@@ -230,7 +230,7 @@ It provides detailed information about the time taken for each module to compile
 1. Once the trace server is running you can view the trace at https://trace.nextjs.org/.
 1. By default the trace viewer will aggregate timings, in order to see each individual time you can switch from "Aggregated in order" to "Spans in order" at the top right of the viewer.
 
-> **Good to know**: The trace file is place under the development server directory, which defaults to `.next/dev`. This is controllable using the [`isolatedDevBuild`](/docs/app/api-reference/config/next-config-js/isolatedDevBuild) flag in your Next config file.
+> **Good to know**: The trace file is placed under the development server directory, which defaults to `.next/dev`.
 
 ### Still having problems?
 

docs/01-app/02-guides/upgrading/version-16.mdx

@@ -871,7 +871,7 @@ module.exports = {
 
 ## Concurrent `dev` and `build`
 
-`next dev` and `next build` now use separate output directories, enabling concurrent execution. The `next dev` command outputs to `.next/dev`. This is the new default behavior, controlled by [isolatedDevBuild](/docs/app/api-reference/config/next-config-js/isolatedDevBuild).
+`next dev` and `next build` now use separate output directories, enabling concurrent execution. The `next dev` command outputs to `.next/dev`.
 
 Additionally, a lockfile mechanism prevents multiple `next dev` or `next build` instances on the same project.
 

docs/01-app/03-api-reference/06-cli/next.mdx

@@ -41,7 +41,11 @@ The following commands are available:
 
 ### `next dev` options
 
-`next dev` starts the application in development mode with Hot Module Reloading (HMR), error reporting, and more. The following options are available when running `next dev`:
+`next dev` starts the application in development mode with Hot Module Reloading (HMR), error reporting, and more.
+
+> **Good to know**: Development builds output to `.next/dev` instead of `.next`. This allows you to run `next dev` and `next build` concurrently without conflicts.
+
+The following options are available when running `next dev`:
 
 | Option                                   | Description                                                                                                                                          |
 | ---------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
@@ -175,7 +179,7 @@ The following options are available for the `next typegen` command:
 | `-h, --help`  | Show all available options.                                                                  |
 | `[directory]` | A directory on which to generate types. If not provided, the current directory will be used. |
 
-Output files are written to `<distDir>/types` (typically: `.next/dev/types` or `.next/types`, see [`isolatedDevBuild`](/docs/app/api-reference/config/next-config-js/isolatedDevBuild)):
+Output files are written to `<distDir>/types` (typically: `.next/dev/types` in development or `.next/types` in production):
 
 ```bash filename="Terminal"
 next typegen

docs/01-app/03-api-reference/08-turbopack.mdx

@@ -257,7 +257,7 @@ NEXT_TURBOPACK_TRACING=1 next dev
 
 This will produce a `.next/dev/trace-turbopack` file. Include that file when creating a GitHub issue on the [Next.js repo](https://github.com/vercel/next.js) to help us investigate.
 
-By default the development server outputs to `.next/dev`. Read more about [isolatedDevBuild](/docs/app/api-reference/config/next-config-js/isolatedDevBuild).
+By default the development server outputs to `.next/dev`.
 
 ## Summary
 

jest.config.js

@@ -1,3 +1,4 @@
+const path = require('path')
 const nextJest = require('next/jest')
 
 const createJestConfig = nextJest()
@@ -27,6 +28,10 @@ const customJestConfig = {
   },
 }
 
+if (process.env.CI) {
+  customJestConfig.cacheDirectory = path.join(__dirname, '.jest-cache')
+}
+
 // Check if the environment variable is set to enable test report,
 // Insert a reporter to generate a junit report to upload.
 //

package.json

@@ -198,7 +198,7 @@
     "eslint-plugin-jsdoc": "48.0.4",
     "eslint-plugin-mdx": "3.1.5",
     "eslint-plugin-react": "7.37.0",
-    "eslint-plugin-react-hooks": "0.0.0-experimental-10680271-20260126",
+    "eslint-plugin-react-hooks": "0.0.0-experimental-230772f9-20260128",
     "event-stream": "4.0.1",
     "execa": "2.0.3",
     "expect": "29.7.0",
@@ -258,16 +258,16 @@
     "pretty-ms": "7.0.0",
     "random-seed": "0.3.0",
     "react": "19.0.0",
-    "react-builtin": "npm:react@19.3.0-canary-10680271-20260126",
+    "react-builtin": "npm:react@19.3.0-canary-230772f9-20260128",
     "react-dom": "19.0.0",
-    "react-dom-builtin": "npm:react-dom@19.3.0-canary-10680271-20260126",
-    "react-dom-experimental-builtin": "npm:react-dom@0.0.0-experimental-10680271-20260126",
-    "react-experimental-builtin": "npm:react@0.0.0-experimental-10680271-20260126",
-    "react-is-builtin": "npm:react-is@19.3.0-canary-10680271-20260126",
-    "react-server-dom-turbopack": "19.3.0-canary-10680271-20260126",
-    "react-server-dom-turbopack-experimental": "npm:react-server-dom-turbopack@0.0.0-experimental-10680271-20260126",
-    "react-server-dom-webpack": "19.3.0-canary-10680271-20260126",
-    "react-server-dom-webpack-experimental": "npm:react-server-dom-webpack@0.0.0-experimental-10680271-20260126",
+    "react-dom-builtin": "npm:react-dom@19.3.0-canary-230772f9-20260128",
+    "react-dom-experimental-builtin": "npm:react-dom@0.0.0-experimental-230772f9-20260128",
+    "react-experimental-builtin": "npm:react@0.0.0-experimental-230772f9-20260128",
+    "react-is-builtin": "npm:react-is@19.3.0-canary-230772f9-20260128",
+    "react-server-dom-turbopack": "19.3.0-canary-230772f9-20260128",
+    "react-server-dom-turbopack-experimental": "npm:react-server-dom-turbopack@0.0.0-experimental-230772f9-20260128",
+    "react-server-dom-webpack": "19.3.0-canary-230772f9-20260128",
+    "react-server-dom-webpack-experimental": "npm:react-server-dom-webpack@0.0.0-experimental-230772f9-20260128",
     "react-ssr-prepass": "1.0.8",
     "react-virtualized": "9.22.3",
     "relay-compiler": "13.0.2",
@@ -277,8 +277,8 @@
     "resolve-from": "5.0.0",
     "sass": "1.54.0",
     "satori": "0.15.2",
-    "scheduler-builtin": "npm:scheduler@0.28.0-canary-10680271-20260126",
-    "scheduler-experimental-builtin": "npm:scheduler@0.0.0-experimental-10680271-20260126",
+    "scheduler-builtin": "npm:scheduler@0.28.0-canary-230772f9-20260128",
+    "scheduler-experimental-builtin": "npm:scheduler@0.0.0-experimental-230772f9-20260128",
     "seedrandom": "3.0.5",
     "semver": "7.3.7",
     "serve-handler": "6.1.6",
@@ -323,10 +323,10 @@
       "@types/react-dom": "19.2.3",
       "@types/retry": "0.12.0",
       "jest-snapshot": "30.0.0-alpha.6",
-      "react": "19.3.0-canary-10680271-20260126",
-      "react-dom": "19.3.0-canary-10680271-20260126",
-      "react-is": "19.3.0-canary-10680271-20260126",
-      "scheduler": "0.28.0-canary-10680271-20260126"
+      "react": "19.3.0-canary-230772f9-20260128",
+      "react-dom": "19.3.0-canary-230772f9-20260128",
+      "react-is": "19.3.0-canary-230772f9-20260128",
+      "scheduler": "0.28.0-canary-230772f9-20260128"
     },
     "packageExtensions": {
       "eslint-plugin-react-hooks@0.0.0-experimental-6de32a5a-20250822": {
@@ -339,7 +339,8 @@
       "webpack-sources@3.2.3": "patches/webpack-sources@3.2.3.patch",
       "stacktrace-parser@0.1.10": "patches/stacktrace-parser@0.1.10.patch",
       "@types/node@20.17.6": "patches/@types__node@20.17.6.patch",
-      "taskr@1.1.0": "patches/taskr@1.1.0.patch"
+      "taskr@1.1.0": "patches/taskr@1.1.0.patch",
+      "minizlib@3.1.0": "patches/minizlib@3.1.0.patch"
     }
   }
 }

packages/create-next-app/package.json

@@ -32,7 +32,6 @@
     "@types/cross-spawn": "6.0.0",
     "@types/node": "20.14.2",
     "@types/prompts": "2.4.2",
-    "@types/tar": "6.1.13",
     "@types/validate-npm-package-name": "4.0.2",
     "@vercel/ncc": "0.38.1",
     "async-retry": "1.3.1",
@@ -44,7 +43,7 @@
     "picocolors": "1.0.0",
     "prettier-plugin-tailwindcss": "0.6.2",
     "prompts": "2.4.2",
-    "tar": "7.4.3",
+    "tar": "7.5.7",
     "update-check": "1.5.4",
     "validate-npm-package-name": "5.0.1"
   },

packages/next/package.json

@@ -212,7 +212,6 @@
     "@types/send": "0.14.4",
     "@types/serve-handler": "6.1.4",
     "@types/shell-quote": "1.7.1",
-    "@types/tar": "6.1.5",
     "@types/text-table": "0.2.1",
     "@types/ua-parser-js": "0.7.36",
     "@types/webpack-sources1": "npm:@types/webpack-sources@0.1.5",
@@ -333,7 +332,7 @@
     "strip-ansi": "6.0.0",
     "style-loader": "4.0.0",
     "superstruct": "1.0.3",
-    "tar": "6.1.15",
+    "tar": "7.5.7",
     "taskr": "1.1.0",
     "terser": "5.27.0",
     "terser-webpack-plugin": "5.3.9",

packages/next/src/build/index.ts

@@ -2835,10 +2835,6 @@ export default async function build(
           featureName: 'experimental/ppr',
           invocationCount: config.experimental.ppr ? 1 : 0,
         },
-        {
-          featureName: 'experimental/isolatedDevBuild',
-          invocationCount: config.experimental.isolatedDevBuild ? 1 : 0,
-        },
         {
           featureName: 'turbopackFileSystemCache',
           invocationCount: isFileSystemCacheEnabledForBuild(config) ? 1 : 0,

packages/next/src/build/type-check.ts

@@ -29,7 +29,6 @@ function verifyTypeScriptSetup(
   enableWorkerThreads: boolean | undefined,
   hasAppDir: boolean,
   hasPagesDir: boolean,
-  isolatedDevBuild: boolean | undefined,
   appDir: string | undefined,
   pagesDir: string | undefined,
   debugBuildPaths: { app: string[]; pages: string[] } | undefined
@@ -60,7 +59,6 @@ function verifyTypeScriptSetup(
       cacheDir,
       hasAppDir,
       hasPagesDir,
-      isolatedDevBuild,
       appDir,
       pagesDir,
       debugBuildPaths,
@@ -130,7 +128,6 @@ export async function startTypeChecking({
           config.experimental.workerThreads,
           !!appDir,
           !!pagesDir,
-          config.experimental.isolatedDevBuild,
           appDir,
           pagesDir,
           debugBuildPaths

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

@@ -147,7 +147,6 @@ async function runPlaywright(
       disableStaticImages: nextConfig.images.disableStaticImages,
       hasAppDir: !!appDir,
       hasPagesDir: !!pagesDir,
-      isolatedDevBuild: nextConfig.experimental.isolatedDevBuild,
       appDir: appDir || undefined,
       pagesDir: pagesDir || undefined,
     })

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

@@ -67,7 +67,6 @@ const nextTypegen = async (
     disableStaticImages: nextConfig.images.disableStaticImages,
     hasAppDir: !!appDir,
     hasPagesDir: !!pagesDir,
-    isolatedDevBuild: nextConfig.experimental.isolatedDevBuild,
     appDir: appDir || undefined,
     pagesDir: pagesDir || undefined,
   })