Template for Haskell + Nix projects.

Nix-based Haskell template containing ghc, cabal, hoogle, ormolu, and haskell-language-server.

Usage

Clone/copy this repo to the intended package location, and run the wizard.

git clone https://github.com/jonascarpay/template-haskell <my-project>
cd <my-project>
./wizard.sh

You can enter the Nix shell with nix develop. Running cabal from inside this shell should use the packages that have been pre-built by Nix.

You can also build your project entirely with nix using nix build.

CI

Default CI consists of a Stack matrix, Cabal matrix, and Nix build. Don't forget to look at .github/workflows/CI.yaml and tweak this to your project.

Deprecations

haskell.nix

This template previously used IOHK's haskell.nix. Since I initially released this template and the accompanying blog post, the vanilla Nix Haskell infrastructure has become significantly easier to use, and I now recommend it for most users. I have decided to stop maintaining the haskell.nix branch.

Non-flake interface

Since both I and all users I've talked to never use the non-flakes version anymore, I have decided to drop support for it. So, template-haskell is now flakes-only.

Don't worry if you have not used flakes before, the practical implications of this change are minimal. After enabling flakes support, just use nix build and nix develop instead of nix-build and nix-shell, respectively.