Input Ignored in Library Mode in v3

[incutonez]

Describe the bug

Apologies if this has been reported... I was looking through the backlog (and change log) and didn't find anything that was exactly this issue (#9086 could be related).

Anyway, I have a library mode package that includes some extra files in the input option. This works in v2, but it doesn't work in v3... just open the fiddle and type npm run build.

In the v2 one, you'll see this output (which is expected):

❯ npm run build
$ vite build
vite v2.9.15 building for production...
✓ 2 modules transformed.
dist/file1.js   0.03 KiB / gzip: 0.05 KiB
dist/file2.js   0.03 KiB / gzip: 0.05 KiB

In v3, you'll see this output:

❯ npm run build
$ vite build
vite v3.0.9 building for production...
✓ 1 modules transformed.
dist/index.js   0.05 KiB / gzip: 0.07 KiB

Let me know if any other info is needed.

Reproduction

https://stackblitz.com/edit/vitejs-vite-n1ynjz?file=vite.config.js,index.js,package.json

System Info

Whatever StackBlitz uses, which I believe is Linux but also locally:


  System:
    OS: Windows 10 10.0.19042
    CPU: (12) x64 Intel(R) Core(TM) i7-10850H CPU @ 2.70GHz
    Memory: 14.74 GB / 31.75 GB
  Binaries:
    Node: 16.14.2 - C:\Program Files\nodejs\node.EXE
    npm: 8.5.0 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: Spartan (44.19041.1266.0), Chromium (103.0.1264.77)
    Internet Explorer: 11.0.19041.1566
  npmPackages:
    @vitejs/plugin-vue: ^3.0.3 => 3.0.3
    vite: ^3.0.9 => 3.0.9

### Used Package Manager

npm

### Logs

_No response_

### Validations

- [X] Follow our [Code of Conduct](https://github.com/vitejs/vite/blob/main/CODE_OF_CONDUCT.md)
- [X] Read the [Contributing Guidelines](https://github.com/vitejs/vite/blob/main/CONTRIBUTING.md).
- [X] Read the [docs](https://vitejs.dev/guide).
- [X] Check that there isn't [already an issue](https://github.com/vitejs/vite/issues) that reports the same bug to avoid creating a duplicate.
- [X] Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to [vuejs/core](https://github.com/vuejs/core) instead.
- [X] Check that this is a concrete bug. For Q&A open a [GitHub Discussion](https://github.com/vitejs/vite/discussions) or join our [Discord Chat Server](https://chat.vitejs.dev/).
- [X] The provided reproduction is a [minimal reproducible example](https://stackoverflow.com/help/minimal-reproducible-example) of the bug.

[sapphi-red]

Yes, it's a duplicate of #9086, #9701.
(I've updated the title of #9086 now as it was a bit difficult to understand correctly)