haskell: Add hoogle option to developPackage

[expipiplus1]

Also add composeExtensionss to lib.

This seems to be a sensible way of getting ghcWithHoogle into the mix.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[expipiplus1]

name hoogle -> withHoogle for consistency with other makeShell

[cdepillabout]

I left a few comments.

Also, it would be nice if you wrote some documentation for end users who want to use Hoogle. Could you add a sentence or two for what an end user would be able to do by enabling the withHoogle option? I'm guessing the idea is that they now get a hoogle in their path with a database of all dependencies?

It'd also be nice to have a test for developPackage (similar to the test for shellFor), but that's more of a wish-list type thing. Not having a test shouldn't block this from being merged in.

[expipiplus1]

It'd also be nice to have a test for developPackage (similar to the test for shellFor), but that's more of a wish-list type thing. Not having a test shouldn't block this from being merged in.

Such a test would involve import-from-derivation, is that permissible in nixpkgs?

[cdepillabout]

Such a test would involve import-from-derivation, is that permissible in nixpkgs?

Ah, good call.

I guess you could always just mark it __noChroot and we could use it as a test that we run manually, but it would be unfortunate that we couldn't have it run by Hydra.

[expipiplus1]

Such a test would involve import-from-derivation, is that permissible in nixpkgs?

Ah, good call.

I guess you could always just mark it __noChroot and we could use it as a test that we run manually, but it would be unfortunate that we couldn't have it run by Hydra.

Right, perhaps best for another PR

[cdepillabout]

Aside from the one remaining comment, I think this looks really good.

I'm going to leave this open for a few days, so that any else that got notified has a chance to comment on the change in lib/.

@expipiplus1 If there are no additional comments to this in a few days, please feel free to ping me and I will merge it in (assuming the test thing has been fixed).

[expipiplus1]

Will do, thanks

[expipiplus1]

@cdepillabout ping!

[expipiplus1]

I don't think that @ofborg's failure is to do with this PR

[expipiplus1]

Thanks!

[FRidh]

composeManyExtensions was proposed in #33258.