Vite HMR blank page when editing `__root.tsx` (Solid SSR)

Which project does this relate to?

Router

Describe the bug

Editing __root.tsx triggers HMR but renders blank page with client error:

Warning: template2 is not a function

Server-side stack trace:

RunnerError
  at reviveInvokeError (vite/dist/node/module-runner.js:476:64)
  at Object.invoke (vite/dist/node/module-runner.js:549:11)
  at ModuleRunner.getModuleInformation (vite/dist/node/module-runner.js:1086:7)
  at request (vite/dist/node/module-runner.js:1103:83)
  at /src/routeTree.gen.ts:11:1              ← import { Route as rootRouteImport } from './routes/__root'
  at ESModulesEvaluator.runInlinedModule (vite/dist/node/module-runner.js:913:3)
  at ModuleRunner.directRequest (vite/dist/node/module-runner.js:1146:59)
  at ModuleRunner.cachedRequest (vite/dist/node/module-runner.js:1053:73)
  at /src/router.tsx:4:1                           ← import { routeTree } from '~/routeTree.gen'
  at ESModulesEvaluator.runInlinedModule (vite/dist/node/module-runner.js:913:3)

status: 500

HMR works correctly on all other route files.

Your Example Website or App

n/a

Steps to Reproduce the Bug or Issue

1. Create TanStack Start (Solid) app
2. pnpm dev
3. Edit __root.tsx (e.g. change some text)
4. Observe: Blank page, console shows template2 is not a function
5. Compare: Edit index.tsx → HMR works fine

Expected behavior

Expected: Either successful HMR or graceful full reload
Actual: Blank page requiring manual refresh

Screenshots or Videos

No response

Platform

• Router / Start Version: 1.145.11
• OS: macOS
• Browser: Chrome
• Browser Version: 144.0
• Bundler: Vite
• Bundler Version: 7.3.0

Additional context

No response

Start with the generated import in routeTree.gen.ts and its use from router.tsx, then inspect the routes/__root.tsx HMR path alongside the Vite module-runner stack trace. Reproduce with pnpm dev by editing __root.tsx, compare with index.tsx, and consider the issue complete when root edits no longer produce a blank page or require a manual refresh.