Haskell+Nix, One Package

.gitignore

/dist/
/dist-*/
/result
/result-*
cabal.project.local
Setup

README.org

Fixup (work around gist limitations)

mkdir app ; git mv app{_slash_,/}Main.hs

Commands

Clean full build

nix-build

Dev mode

nix-shell

Then you can build with cabal v1-build or cabal build with or without --nix=True (or $HOME/.cabal/config containing nix: True).

app_slash_Main.hs

module Main where

main = putStrLn "Hello, World!"

default.nix

{ pkgs ? import <nixpkgs> {} }:
let
  src = builtins.fetchGit {
     url = ./.;
  };
in pkgs.haskellPackages.callCabal2nix "" src {}

example.cabal

cabal-version:      3.0
name:               example
version:            0.1.0.0

build-type:         Simple

-- This could be split up into lib or src folder and app folder,
-- a library with most of the code and an executable that exposes it as a CLI,
-- as many projects prefer. Here, it has been kept simplistic/minimal.
executable example
    main-is:          Main.hs

    build-depends:
          base
    hs-source-dirs:   app
    default-language: Haskell2010

shell.nix

{ pkgs ? import <nixpkgs> {} }:
(pkgs.haskell.lib.addBuildTool
  (import ./. { inherit pkgs; })
  pkgs.cabal-install
).env