TypeError: selector is not a function

Which project does this relate to?

Start

Describe the bug

This is my first time trying out tanstack start and I run into an issue trying to run the app with pnpm dev.

I chose AI, DB, Form, Query and I also chose Netlify

Here are the logs:

Initially looks like everything is ok

❯ pnpm dev

> tanstack-experiments@ dev /Users/aalmacin/Projects/tanstack-experiments
> vite dev --port 3000

11:48:44 p.m. [vite] ⬥ Netlify Environment loaded
11:48:44 p.m. [vite] ⬥ Netlify Middleware loaded. Emulating features: aiGateway, blobs, edgeFunctions, environmentVariables, functions, geolocation, headers, images, redirects, static.
11:48:44 p.m. [vite] ⬥ Netlify 💭 Linking this project to a Netlify site lets you deploy your site, use any environment variables defined on your team and site and much more. Run npx netlify init to get started.

  VITE v7.3.1  ready in 1831 ms

  ➜  Local:   http://localhost:3000/
  ➜  Network: use --host to expose
  ➜  press h + enter to show help

But I am getting {"status":500,"unhandled":true,"message":"HTTPError"} on the browser when I tried to open http://localhost:3000/. On the terminal it shows:

TypeError: selector is not a function
    at memoizedSelector (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/use-sync-external-store@1.6.0_react@19.2.4/node_modules/use-sync-external-store/cjs/use-sync-external-store-shim/with-selector.development.js:47:30)
    at /Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/use-sync-external-store@1.6.0_react@19.2.4/node_modules/use-sync-external-store/cjs/use-sync-external-store-shim/with-selector.development.js:76:26
    at Object.useSyncExternalStore (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/react-dom@19.2.4_react@19.2.4/node_modules/react-dom/cjs/react-dom-server.node.development.js:10232:18)
    at process.env.NODE_ENV.exports.useSyncExternalStore (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/react@19.2.4/node_modules/react/cjs/react.development.js:1270:34)
    at process.env.NODE_ENV.exports.useSyncExternalStoreWithSelector (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/use-sync-external-store@1.6.0_react@19.2.4/node_modules/use-sync-external-store/cjs/use-sync-external-store-shim/with-selector.development.js:82:19)
    at useStore (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/@tanstack+react-store@0.9.2_react-dom@19.2.4_react@19.2.4__react@19.2.4/node_modules/@tanstack/react-store/src/useStore.ts:35:28)
    at AIAssistant (/Users/aalmacin/Projects/tanstack-experiments/src/components/demo-AIAssistant.tsx:82:18)
    at Object.react_stack_bottom_frame (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/react-dom@19.2.4_react@19.2.4/node_modules/react-dom/cjs/react-dom-server.node.development.js:10288:18)
    at renderWithHooks (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/react-dom@19.2.4_react@19.2.4/node_modules/react-dom/cjs/react-dom-server.node.development.js:5298:19)
    at renderElement (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/react-dom@19.2.4_react@19.2.4/node_modules/react-dom/cjs/react-dom-server.node.development.js:5733:23)
TypeError: selector is not a function
    at memoizedSelector (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/use-sync-external-store@1.6.0_react@19.2.4/node_modules/use-sync-external-store/cjs/use-sync-external-store-shim/with-selector.development.js:47:30)
    ... 8 lines matching cause stack trace ...
    at renderElement (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/react-dom@19.2.4_react@19.2.4/node_modules/react-dom/cjs/react-dom-server.node.development.js:5733:23) {
  cause: TypeError: selector is not a function
      at memoizedSelector (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/use-sync-external-store@1.6.0_react@19.2.4/node_modules/use-sync-external-store/cjs/use-sync-external-store-shim/with-selector.development.js:47:30)
      at /Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/use-sync-external-store@1.6.0_react@19.2.4/node_modules/use-sync-external-store/cjs/use-sync-external-store-shim/with-selector.development.js:76:26
      at Object.useSyncExternalStore (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/react-dom@19.2.4_react@19.2.4/node_modules/react-dom/cjs/react-dom-server.node.development.js:10232:18)
      at process.env.NODE_ENV.exports.useSyncExternalStore (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/react@19.2.4/node_modules/react/cjs/react.development.js:1270:34)
      at process.env.NODE_ENV.exports.useSyncExternalStoreWithSelector (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/use-sync-external-store@1.6.0_react@19.2.4/node_modules/use-sync-external-store/cjs/use-sync-external-store-shim/with-selector.development.js:82:19)
      at useStore (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/@tanstack+react-store@0.9.2_react-dom@19.2.4_react@19.2.4__react@19.2.4/node_modules/@tanstack/react-store/src/useStore.ts:35:28)
      at AIAssistant (/Users/aalmacin/Projects/tanstack-experiments/src/components/demo-AIAssistant.tsx:82:18)
      at Object.react_stack_bottom_frame (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/react-dom@19.2.4_react@19.2.4/node_modules/react-dom/cjs/react-dom-server.node.development.js:10288:18)
      at renderWithHooks (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/react-dom@19.2.4_react@19.2.4/node_modules/react-dom/cjs/react-dom-server.node.development.js:5298:19)
      at renderElement (/Users/aalmacin/Projects/tanstack-experiments/node_modules/.pnpm/react-dom@19.2.4_react@19.2.4/node_modules/react-dom/cjs/react-dom-server.node.development.js:5733:23),
  status: 500,
  statusText: undefined,
  headers: undefined,
  data: undefined,
  body: undefined,
  unhandled: true
}

Your Example Website or App

https://github.com/aalmacin/tanstack-experiments

Steps to Reproduce the Bug or Issue

Commands:
Choose Netlify and AI, DB, Form, Query

pnpm create @tanstack/start@latest
pnpm dev

Expected behavior

As a new user, I expect to see the sample home page.

Screenshots or Videos

No response

Platform

• Router / Start Version: latest
• OS: MacOS Tahoe Version 26.3.1
• Chip: Apple M4 Pro
• Browser: Chrome
• Browser Version: 145.0.7632.160
• Bundler: vite
• Bundler Version: 7.3.1
• Node version: v23.11.0

Additional context

No response

Riproduci l’app generata con pnpm create @tanstack/start@latest, selezionando Netlify e AI, DB, Form e Query, quindi esegui pnpm dev. Inizia da src/components/demo-AIAssistant.tsx:82 e segui la chiamata useStore che non riesce durante il rendering lato server; il lavoro è completato quando la home page di esempio viene caricata senza il TypeError.