{ description = "haskell-template's description"; inputs = { nixpkgs.url = "github:nixos/nixpkgs/568e0bc498ee51fdd88e1e94089de05f2fdbd18b"; flake-utils.url = "github:numtide/flake-utils"; flake-compat = { url = "github:edolstra/flake-compat"; flake = false; }; }; outputs = inputs@{ self, nixpkgs, flake-utils, ... }: flake-utils.lib.eachSystem [ "x86_64-linux" "x86_64-darwin" "aarch64-darwin" ] (system: let overlays = [ ]; pkgs = import nixpkgs { inherit system overlays; config.allowBroken = true; }; # https://github.com/NixOS/nixpkgs/issues/140774#issuecomment-976899227 m1MacHsBuildTools = pkgs.haskellPackages.override { overrides = self: super: let workaround140774 = hpkg: with pkgs.haskell.lib; overrideCabal hpkg (drv: { enableSeparateBinOutput = false; }); in { ghcid = workaround140774 super.ghcid; ormolu = workaround140774 super.ormolu; }; }; project = returnShellEnv: pkgs.haskellPackages.developPackage { inherit returnShellEnv; name = "haskell-template"; root = ./.; withHoogle = false; overrides = self: super: with pkgs.haskell.lib; { # Use callCabal2nix to override Haskell dependencies here # cf. https://tek.brick.do/K3VXJd8mEKO7 # Example: # > NanoID = self.callCabal2nix "NanoID" inputs.NanoID { }; # Assumes that you have the 'NanoID' flake input defined. }; modifier = drv: pkgs.haskell.lib.addBuildTools drv (with (if system == "aarch64-darwin" then m1MacHsBuildTools else pkgs.haskellPackages); [ # Specify your build/dev dependencies here. cabal-fmt cabal-install ghcid haskell-language-server ormolu pkgs.nixpkgs-fmt ]); }; in { # Used by `nix build` & `nix run` (prod exe) defaultPackage = project false; # Used by `nix develop` (dev shell) devShell = project true; }); }