Project reference build error when one of projects' exported var contains external module's vars.

Bug Report

🔎 Search Terms

Project Reference.

🕗 Version & Regression Information

• This is a crash
• This changed between versions ______ and _______
• This is the behavior in every version I tried, and I reviewed the FAQ for entries about ProjectReference
• I was unable to test this on prior versions because _______

⏯ Playground Link

https://github.com/07akioni/project-reference-build-error

💻 Code

// proj1/index.ts
import { enUS } from 'date-fns/locale'

const myLocale = {
  name: 'enUS',
  locale: enUS
}

export {
  myLocale
}

// proj2/index.ts
import { myLocale } from 'proj1'

console.log(myLocale)

🙁 Actual behavior

error TS2304: Cannot find name 'Locale'

🙂 Expected behavior

It works.