Why is `nixpkgs.haskellPackages.time` null?

I try running the following in nix-repl:

nix-repl> pkgs = import <nixpkgs> {}
nix-repl> pkgs.haskellPackages.time

The same seems to be true for some other packages (such as containers and unix), and for different compiler versions. I would expect a derivation for a Haskell package there, as is the case for other packages like servant or conduit.

Does anyone know why this is? Just curious!

Those packages are shipped as a part of GHC. They still exist as attributes in haskellPackages so that the output of cabal2nix doesn’t have to know which packages are shipped in GHC.


I appreciate it, thank you so much!