Re: Try to depend on imported derivations

[Chris Warburton]

This is a bit too vague in scope. We're better off keeping it in mind as
a "design pattern", rather than thinking of it as a one-off task. In
particular, we no longer use the 'haskellPkgDeps' and friends mentioned
in the original issue, since the haskell.nix infrastructure from IOHK
does a better job and is maintained by other people.

Hence I'm closing this off as not requiring any specific work right now,
even though it's an important issue to keep in mind in the future.