mappend is no longer pulled in as a side-effect

nix-community / emacs2nix

Automatically generate Nix expressions for Emacs packages

GNU General Public License v3.0

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mappend is no longer pulled in as a side-effect #36

Closed mdorman closed 7 years ago

mdorman commented 7 years ago

Looks like the move to stackage-8.0 brought in a version that no longer exported mappend by default.

ttuegel commented 7 years ago

Data.Monoid is a base module, so I'm not sure how that could be. How are you building this?

mdorman commented 7 years ago

It's a base module, but <> isn't (and hasn't been) re-exported by Prelude.

ttuegel commented 7 years ago

How are you building? The project shell.nix should set you up with GHC 8.0, wherein Prelude should export it. If that's not happening, there are two bugs!

mdorman commented 7 years ago

Sorry for my delay in responding, $WORK has been sucking up all of my available time.

Although I do have a few tweaks in my build environment, you can easily reproduce the failure for yourself by just updating the nixpkgs submodule to the current unstable.

And while <> was in base, it was never exported by Prelude, and the files this modifies do not include Data.Monoid directly---so they were pulling in <> indirectly via something that stopped re-exporting it.