I'm currently having issue with the multi public library feature on Cabal 3.0. 

I have a `main` package that has a dependency on `sub` package that exports main and sub library

But when I try to build it, I got an error saying 

cabal: Encountered missing or private dependencies:

sub : {sub, sublib} ==0.1.0.0 

I have `visibility: true` on my library stanza, and I have cabal-install 3.0 installed, I couldn't figure out what's wrong. I've come across this issue https://github.com/haskell/cabal/issues/6039, and I'm not sure whether it's related to my issue.

Here's an example of the code I have: https://github.com/jeffhappily/test

Best regards,
Jeff