https://haskell4nix.readthedocs.io/
https://github.com/NixOS/cabal2nix/tree/master/doc

https://haskell4nix.readthedocs.io/nixpkgs-users-guide.html
https://haskell4nix.readthedocs.io/nixpkgs-developers-guide.html
https://haskell4nix.readthedocs.io/frequently-asked-questions.html
https://haskell4nix.readthedocs.io/external-resources.html