[Nix-dev] Publish All of Hackage

[Peter Simons]

Hi Oliver,

 > [You really want to commit] the scripts that *generate* the 50mb file
 > as some sort of Nix expression. Then, when I as a user choose to
 > evaluate the set of Haskell packages, I will be forced to generate
 > all the Nix expressions - or, this being Nix, ask a binary
 > substitution server for that.

you are right -- that is totally what we should do, and we *can* do it
with Nix today, because we can import from a store derivation during
evaluation. Thank you for the suggestion!

Now, I suppose this begets the question of why we check the "small"
hackage-packages.nix file into Nixpkgs? Shouldn't that be generated
during evaluation, too?

The downside of this approach is that generating the entire Haskell
package set is actually kind of expensive, and we probably wouldn't want
to impose those costs onto random users who just wants to have XMonad
for their window manager, but still ... it's tempting to argue that
generated files should not be part of Nixpkgs. Instead, the generation
process should be.

Best regards,
Peter