Exporting qualified module doesn't export anything from it

Summary

Exporting qualified module doesn't export anything from it.

Steps to reproduce

module Foo (module Bar) where

import qualified X as Bar (foo)

This module doesn't export foo.

But if you remove qualified, like that:

module Foo (module Bar) where

import X as Bar (foo)

it does export foo.

Expected behavior

I expect Foo to export foo in both cases or it should be an error to export qualified module.

Environment

• GHC version used: 8.6.5 (from stack, no nix)

Optional:

• Operating System: Ubuntu 18.04