The Haskell Hackage database allows distros to report which packages they ship, and include a link. Right now, it seems that nixpkgs reports all haskell packags, including broken ones. This makes for a bad user experience – I might see on hackage that nixos comes with a certain package, and then happily go ahead trying to use it, only later to get the dreaded

error: Package ‘proteaaudio-0.9.4’ in /home/jojo/build/nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix:236858 is marked as broken, refusing to evaluate.

error message.

Same actually for repology, reporting packages as available that we know do not build is not great.