vercel/next.js v15.2.0-canary.40

on GitHub

Core Changes

• fix: preserve custom Vary headers: #75536
• Clean-up: remove unused errorMessage param in stack frames: #75554
• Upgrade React from 37906d4d-20250127 to c492f975-20250128: #75434
• Fix console replaying and React.cache usage in "use cache" functions: #75520
• Upgrade React from c492f975-20250128 to a4b2d0d5-20250203: #75649
• DX: Reduce devtools clutter by batching stack frame requests: #75557
• Add nodejs runtime support for middleware: #75624
• polish hydration errors: #75632
• feat: added support for prefetch segments when deployed: #75202

Misc Changes

• chore(github): update stale bot: #75630
• perf(turbopack): Update rustc-hash from 1.1.0 to 2.1.0: #75531
• perf(next-custom-transforms): Replace non-Sync Rc<DashMap<_, _>> usage with Rc<RefCell<FxHashMap<_, _>>>: #75534
• refactor(turbopack): Define and use an FxDashMap alias everywhere: #75538
• perf(turbopack): Migrate as many data structures to FxHash as possible: #75546
• Disable rewrite-headers tests that are dependent on Vercel site config: #75647
• docs: remove unused imports: #75653
• Run build-nextjs for Turbopack test runs on metal machines instead of GitHub hosted runner: #75654
• perf: Make next_ssg use Atom instead of String: #75591
• Remove github runner specific step: #75655
• [Turbopack] fix dependencies on own task: #75658
• Turbopack: OutputAsset::path(): #75659
• [Turbopack] use Timestamp type, allow spans less than 1µs: #75479
• Turbopack: generate less JS before minification: #75358
• [Turbopack] correctly apply defines: #75643
• Turbopack: don't cell CodeGen-s: #75513

Credits

Huge thanks to @Timer, @samcx, @bgw, @gaojude, @unstubbable, @leerob, @timneutkens, @kdy1, @sokra, @mischnic, @ijjk, @huozhi, and @wyattjoh for helping!