Reproduction link or steps

1. Create tsconfig.json with a path alias:

   {
       "compilerOptions": {
           "paths": { "#/*": ["./src/*"] }
       },
       "include": ["src/**/*"]
   }

2. Set resolve.tsconfigPaths: true in vite.config.ts:

   import { defineConfig } from "vite";
   export default defineConfig({
       resolve: { tsconfigPaths: true },
   });

3. Import using the alias in src/main.tsx:

   import { Foo } from "#/components/Foo.js";

   (src/components/Foo.tsx exists.)

4. Run vite (dev server) → error. Run vite build → succeeds.

https://stackblitz.com/edit/vitejs-vite-jufdca1x?file=tsconfig.app.json,src%2Fcomponents%2FFoo.tsx,src%2FApp.tsx,src%2Fmain.tsx&terminal=dev

What is expected?

resolve.tsconfigPaths: true resolves tsconfig path aliases in both the dev server and the production build.

What is actually happening?

The dev server fails with:

[plugin:vite:import-analysis] Failed to resolve import "#/components/Foo.js" from "src/main.tsx". Does the file exist?

vite build (Rolldown pipeline) succeeds and transforms all modules correctly. resolve.tsconfigPaths: true appears to only apply to the Rolldown build, not the dev server.

Workaround: adding an explicit resolve.alias alongside tsconfigPaths: true fixes the dev server:

import { fileURLToPath } from "node:url";
resolve: {
    tsconfigPaths: true,
    alias: { "#/": fileURLToPath(new URL("./src/", import.meta.url)) },
}

System Info

System:
    OS: Linux 6.17 Pop!_OS 22.04 LTS
    CPU: (32) x64 13th Gen Intel(R) Core(TM) i9-13900K
    Memory: 45.88 GB / 62.53 GB
    Container: Yes
    Shell: 5.1.16 - /bin/bash
  Binaries:
    Node: 24.13.0 - /home/dasprid/.nvm/versions/node/v24.13.0/bin/node
    Yarn: 1.22.22 - /home/dasprid/.nvm/versions/node/v24.13.0/bin/yarn
    npm: 11.6.2 - /home/dasprid/.nvm/versions/node/v24.13.0/bin/npm
    pnpm: 10.32.1 - /home/dasprid/.nvm/versions/node/v24.13.0/bin/pnpm
  Browsers:
    Chrome: 146.0.7680.80
    Firefox: 148.0.2
    Firefox Developer Edition: 148.0.2

Any additional comments?

No response