Next.js hardens Turbopack while Expo tightens its development loop

Turbopack gets leaner and steadier

Next.js devoted most of its week to Turbopack, shipping a run of canary updates that mostly make the bundler cheaper to run and less confusing when things go wrong. Cache size came down through per-family compression and the worker thread for builds was removed entirely, alongside updates to the malloc backend for memory reporting. Developers chasing flaky behavior got two targeted repairs: HMR now recovers properly after a dropped connection, and CSS sourcemaps carry the correct source field while dynamic access tracking in final runtime prerenders was corrected.

Editor and runtime correctness also got attention. Route info segment overrides now refresh in the dev overlay instead of displaying stale values, and unrecognized Server Actions return client errors so callers see a real failure rather than silence. Cache Components gained clearer, shorter "use cache" error messages and documentation on preloading, plus correct handling of original searchParams for private-cache pages.

The architectural direction is visible in smaller changes too: Edge runtime handling was removed from use-cache-wrapper, consistent with Next.js 16 stepping away from Edge runtime support. Adapter route collapses are now on by default, and quiet cleanup landed in next info so a missing package manager no longer produces a confusing error.

For teams on stable releases, two backports arrived. Next.js re-enabled AVIF image optimization for both the 16.x line, restoring AVIF alongside fixes for recursion in testmode fetch and TypeScript aliasing build errors, and the 15.x line, bringing AVIF back when newer sharp versions are installed. Both correct regressions introduced by the immediately preceding patches, so upgrading past those versions is worthwhile.

Expo tightens and extends its development loop

The most consequential Expo change this week is a policy shift: Expo Go now requires users to be logged into both the CLI and the app to run projects in development mode. The requirement currently applies only to the latest iOS build, leaving Android and simulator users unaffected, and development builds remain exempt. Still, anyone relying on Expo Go for a quick iOS check should expect an authentication step they didn't need before.

EAS CLI, meanwhile, shipped two updates that expand what you can do without leaving the terminal. Workflow jobs can now be inspected live over SSH via eas workflow:ssh, with --ssh available on workflow:run as well, plus --tag filtering for simulator sessions and real-time workflow log streaming. The other update makes project scaffolding more flexible: eas new prompts for the Expo SDK version with a matching flag, pulling templates from npm so SDK-specific versions resolve correctly. The same work adds EAS_PNPM_FILTER_WORKSPACE support for pnpm monorepo builds and retries deploy commands dynamically based on payload size.

Svelte's September roundup

Svelte's monthly post covers a quieter stretch but a meaningful one: the SvelteKit 3 release candidate is nearly ready, and Svelte 5.57 added getOrInsert helpers to SvelteMap for the read-or-initialize pattern many apps hand-roll. The sv CLI replaced its mcp add-on with a broader ai-tools one, and sv@next now offers a task-based migration path for existing SvelteKit apps — a sign the ecosystem tooling is being prepared for the 3.0 transition rather than waiting for it.