[rush] Running rush rebuild to run rollup -c causes a warning tip.

[zhangxuan615]

Summary

The console always prints a warning tip(SUCCESS WITH WARNINGS...) if a sub-package has a build command: rollup -c, when I run rush rebuild in the root directory.
What's even weirder is that it just says there's a warning, but it doesn't provide any details about the warning.

If I run directly the command (rollup -c) in the sub-package directory, no warning will be printed.

So, from my opinion, I just think there is incompatibility in rush and rollup.

Repro steps

1. create a sub-package.
2. install rollup in this sub-package.
3. create a source file "./src/index.js".
   export const a = 1; console.log("test:", a)
4. create a config file for rollup: rollup.config.js:
   module.exports = { input: "src/index.js" }
5. add a script command in package.json: "build": "rollup -c".
6. run run rebuild in the root directory.

Details