Reproduction link or steps

1. Open https://stackblitz.com/edit/github-nci4o6nk-ynvw9kzq?file=src%2Fa.mjs,src%2Findex.mjs
2. npm i runs automatically
3. npm run build runs automatically
4. Build errors with "foo" is not exported by "src/a.mjs".
5. Run node src/index.mjs to check that it's a runtime error rather than a early error

What is expected?

No error happens when building. Error happens at runtime.

What is actually happening?

Error ("foo" is not exported by "src/a.mjs") happens when building.

System Info

Stackblitz

  System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 18.20.3 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.2.3 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    rolldown: 1.0.0-beta.2-commit.2666b23 => 1.0.0-beta.2-commit.f069c5d

Any additional comments?

I found this while testing rolldown-vite on ecosystem-ci.