Vite started from another working directory: plugin-rsc externalizes the app's React-peer dependencies, so build-time and dev PPR shell captures are skipped #1044

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1. ivogt commented on Oct 4, 2026

   

   ivogt

   on Oct 4, 2026

   CollaboratorAuthor

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   Evaluated. The cause is upstream, in @vitejs/plugin-rsc (0.5.35), and it affects dev as well as the build.

   Cause

   plugin-rsc's rsc plugin decides which dependencies the ssr environment must not externalize by crawling for packages with a react peer dependency, and it starts that crawl at the working directory, not at the Vite root (dist/plugin-CLvIS10V.js:759):

   const result = await crawlFrameworkPkgs({
     root: process.cwd(),
     ...

   From the repository root that reads the monorepo's package.json, so the app's own dependencies are not found. The resolved config of the capture's temporary server differs between the two runs in exactly one value, the ssr environment's resolve.noExternal:

   • from the app directory: react, react-dom, server-only, client-only, @vitejs/plugin-rsc, @rangojs/router, @testing-library/react, rango-e2e-deep-context-lib, spin-delay
   • from the repository root: react, react-dom, server-only, client-only, @vitejs/plugin-rsc

   root, cacheDir, dedupe, conditions, optimizeDeps and ssr.external are identical. So from another directory spin-delay is externalized, Node loads it from node_modules with its own react, and the renderer in deps_ssr is a different copy: no dispatcher, useState on null.

   Dev too

   vite tests/cloudflare-basic started from the repository root answers 200, and logs the same Invalid hook call / Cannot read properties of null (reading 'useState') with [rango] Dev shell capture error for /ppr-shell/prerendered/alpha (route keeps runtime capture).

   Confirmed by experiment

   Forcing the temporary server's ssr environment to resolve.noExternal: true (one line in createTempRscServer, src/vite/router-discovery.ts, build only) gives five SHELL OK from the repository root and five from the app directory. Not committed: it is blunt (every dependency goes through the optimizer) and was not tried on the node and vercel presets.

   Forwarding the main config's noExternal to the temporary server does not help: that list comes from the same crawl.

   Options

   1. Upstream: plugin-rsc crawls from the config's root. One line there; the real fix.
   2. In rango, until then: run the same crawl from the Vite root in rango's own config() hook and add what is missing to the ssr environment's noExternal, for the main config and the temporary server, dev and build. About 15 to 25 lines; it duplicates what plugin-rsc does.
   3. Document that vite has to be run from the app directory.

   Also read in the same code, not tested

   • src/vite/utils/package-resolution.ts:20: isInstalledFromNpm() checks node_modules/@rangojs/router under process.cwd().
   • src/vite/plugins/vercel-output.ts:411: let root = process.cwd() (may be overwritten in configResolved).
   • plugin-rsc makes module ids relative to process.cwd() at dist/plugin-CLvIS10V.js:1335 and :1589.
2. ivogt

   changed the title [-]Build-time PPR shells are all skipped when `vite build <dir>` runs from another working directory[/-] [+]Vite started from another working directory: plugin-rsc externalizes the app's React-peer dependencies, so build-time and dev PPR shell captures are skipped[/+] on Oct 4, 2026