on ghc 9.6.3 ghc-pkg list output shows duplicate packages but there is no error messages and ghc-pkg check does not report any problem

Summary

On ghc 9.6.3 ghc-pkg list output shows duplicate packages but there is no error messages and ghc-pkg check does not report any problem

Steps to reproduce

$ ghc-pkg check

Warning: include-dirs: /usr/local/lib/ghc-9.6.3/lib/../lib/x86_64-osx-ghc-9.6.3/directory-1.3.8.1/include doesn't exist or isn't a directory

$ ghc --version The Glorious Glasgow Haskell Compilation System, version 9.6.3

bash-3.2$ ghc-pkg list -f $HOME/.cabal/store/ghc-9.6.3/package.db

Cabal-3.10.1.0

Cabal-3.10.1.0

Cabal-syntax-3.10.1.0

Cabal-syntax-3.10.1.0

...

Expected behavior

I expect ghc-pkg list to give an error if it finds duplicate packages. I also expect ghc-pkg check to give an error

Environment

• GHC version used: 9.6.3

Optional:

• Operating System: macos 14.0
• System Architecture:

$ cd ~/.cabal/store/ghc-9.6.3/package.db

$ ls

Cbl-3.10.1.0-49a8fe1b.conf

Cbl-3.10.1.0-d4791e89.conf

Cbl-syntx-3.10.1.0-c1b57fda.conf

Cbl-syntx-3.10.1.0-e0598c59.conf

...