Topic
Next.js & React in Production
`next dev` is green, `next build` fails; the page is 200 locally and 500 on Vercel. This cluster is about the gap between development and production in Next.js: undefined env variables, DYNAMIC_SERVER_USAGE from a nested server component, and Turbopack crashing on exactly one machine. For App Router developers whose bugs only appear after deploy.
25 articles
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Next.js Environment Variable Undefined in Production? Here's Why
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Muddy Double Image at the Seam Between Two Pinned Sections? Dissolve Through One Base Color, Do Not Stack Two Scenes
August 29, 2026 -
Edited `default-menu.ts`, Shipped It, and Staging Still Points at the Old Route: a Sanity Singleton Shadows the Code Default
August 29, 2026 -
Sanity Webhook Fires but Per-Slug Pages Stay Stale? An Empty Projection Turns It Into `revalidatePath('/glossary/[object Object]')`
August 18, 2026 -
Ticker Says $77k, Table Says $76k: Two Days Chasing a Bug That Was Just a Different Cache Key
August 15, 2026 -
`react-hooks/set-state-in-effect`? 27 React Compiler Lint Errors in Next 16 and Which Ones Deserve a Disable
August 9, 2026 -
`?email=name@domain.com` in the URL Bar: A Newsletter Form That Shipped Without a Handler
August 4, 2026 -
A Page Is 200 in `curl` but the Browser Says couldn't load? RSC Stream 500 From `revalidateTag` During Render and an Exhausted Upstash Quota
August 3, 2026 -
1 Million Sanity CDN Requests Gone Before the Month Ended? `force-dynamic` Turns Every Child Fetch Into `no-store`
August 3, 2026 -
Still Burning 150k Sanity Requests a Day After the Cache Fix? 85% of It Was 4 `layout` Singletons
August 3, 2026 -
`Module not found: Can't resolve '@sanity/ui'`? A Silent Turbopack Build Failure and a Deploy That Never Landed
August 3, 2026 -
Route Only 500s in Production, `pnpm dev` Is Fine? `DYNAMIC_SERVER_USAGE` From an Empty `generateStaticParams` That Reads `searchParams`
July 31, 2026 -
1.7 Million API Calls a Month With Zero Visitors: a 15-Second TTL Times Cache Fragmentation Times Bot Crawl
July 20, 2026 -
Fear & Greed Index Stuck at 72 While the API Says 26: a Hardcoded Placeholder Hiding an Outage
July 18, 2026 -
Cmd+K Search Returns "No matches" for Almost Every Keyword in Prod? The Index Was Built From Placeholders
July 15, 2026 -
Sanity Panel 500s in Prod, API Returns 400 `score() function received unexpected expression`? boost() Only Takes Simple Predicates
July 14, 2026 -
Article Page Is 200 in `pnpm dev` but 500 in Production? `DYNAMIC_SERVER_USAGE` From a Nested Server-Component Fetch
July 14, 2026 -
Production Serving Stale HTML After a Deploy? A `Cannot read properties of undefined (reading 'toFixed')` Was Crashing SSR
July 14, 2026 -
`next dev` Is Green but `next build` Fails Type-Check: Dynamic Element With `ref` and `children` Typed `never`
July 13, 2026 -
Next.js 16 Works on `localhost` but HMR Dies Over a LAN IP? Add `allowedDevOrigins`
July 13, 2026 -
`next dev` Turbopack Crashes With `invariant expected layout router to be mounted` on One Machine Only? A `node_modules` Junction Is the Culprit
July 13, 2026 -
Every Article Page Rendered `not-found`, and the Real Cause Was a Month-End CMS Quota
June 30, 2026 -
CSS Modules Rejects a Data-Attribute Selector: `selector is not pure`
June 28, 2026 -
Background Music Dies Every Time an Anchor Link Is Clicked? `window.location.href` Is a Full Reload
June 28, 2026 -
A Countdown Widget Hitting a Third-Party API Straight From the Browser Every 60 Seconds: One 8-Hour Tab Equals 480 Calls
June 21, 2026