Declaration file generation not working as expected

TypeScript Version: 4.0.0-dev.20200429 (when trying with @next)
TypeScript Version: 3.8.0.0-dev.20200429 (when using my version ^3.8.0)

Search Terms: module resolution, lerna, monorepo, import type, declaration file

Code
Repository https://github.com/Volox/tsc-declaration-issue

To bootstrap and run:

npx lerna bootstrap
npx lerna run compile

Expected behavior: The declaration files generated are only related to the package.

Actual behavior: The declaration files are generated correctly only for lib1 and lib2 have the full tree of declaration files of both packages.

Related Issues: None that I was able to find

Notes:
The generation of declaration files is done correctly if I remove the "paths" property from tsconfig.base.json but I receive compilation errors like:

src/index.ts(1,19): error TS2307: Cannot find module 'lib1'.
src/index.ts(3,24): error TS2307: Cannot find module 'lib1/foo/bar'.

Use the linked Volox/tsc-declaration-issue repository and run npx lerna bootstrap followed by npx lerna run compile. Compare the generated declarations for lib1 and lib2 with and without the paths property in tsconfig.base.json, while checking the reported module-resolution errors. Done means each package emits only its own declaration tree without those errors.