{ description = "A minimal Haskell flake"; inputs = { nixpkgs.url = "github:nixos/nixpkgs/nixos-21.11"; flake-utils = { url = "github:numtide/flake-utils"; inputs.nixpkgs.follows = "nixpkgs"; }; }; outputs = { self, nixpkgs, flake-utils }: flake-utils.lib.eachDefaultSystem (system: let pkgs = import nixpkgs { inherit system; }; haskell = { ghc = pkgs.haskellPackages.ghc; hls = pkgs.haskell-language-server.override { supportedGhcVersions = [ "8107" ]; }; }; in with pkgs; { devShell = mkShell { buildInputs = [ haskell.ghc haskell.hls gdb # GHC depends on LANG so need this package to properly interpret our # files with e.g. tasty-discover. # https://www.reddit.com/r/Nix/comments/jyczts/nixshell_locale_issue/ glibcLocales haskellPackages.cabal-install haskellPackages.ormolu haskellPackages.tasty-discover ]; }; }); }