81 lines
2.3 KiB
Nix
81 lines
2.3 KiB
Nix
{
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description = "Example Haskell flake showing overrides and adding stuff to the dev shell";
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inputs = {
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nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
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flake-utils.url = "github:numtide/flake-utils";
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};
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nixConfig.allow-import-from-derivation = true; # cabal2nix uses IFD
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outputs = { self, nixpkgs, flake-utils }:
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let
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ghcVer = "ghc902";
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makeHaskellOverlay = overlay: final: prev: {
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haskell = prev.haskell // {
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packages = prev.haskell.packages // {
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${ghcVer} = prev.haskell.packages."${ghcVer}".override (oldArgs: {
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overrides =
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prev.lib.composeExtensions (oldArgs.overrides or (_: _: { }))
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(overlay prev);
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});
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};
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};
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};
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out = system:
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let
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pkgs = import nixpkgs {
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inherit system;
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overlays = [ self.overlays.default ];
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config.allowBroken = true;
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};
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in
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{
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packages = rec {
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default = sample;
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sample = pkgs.haskell.packages.${ghcVer}.sample;
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};
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checks = {
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inherit (self.packages.${system}) sample;
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};
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# for debugging
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# inherit pkgs;
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devShells.default =
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let haskellPackages = pkgs.haskell.packages.${ghcVer};
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in
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haskellPackages.shellFor {
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packages = p: [ self.packages.${system}.sample ];
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withHoogle = true;
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buildInputs = with haskellPackages; [
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haskell-language-server
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cabal-install
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];
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# Change the prompt to show that you are in a devShell
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# shellHook = "export PS1='\\e[1;34mdev > \\e[0m'";
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};
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};
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in
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flake-utils.lib.eachDefaultSystem out // {
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# this stuff is *not* per-system
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overlays = {
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default = makeHaskellOverlay (prev: hfinal: hprev:
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let hlib = prev.haskell.lib; in
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{
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sample = hprev.callCabal2nix "sample" ./. { };
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# here's how to do hacks to the package set
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# don't run the test suite
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# fast-tags = hlib.dontCheck hprev.fast-tags;
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#
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# don't check version bounds
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# friendly = hlib.doJailbreak hprev.friendly;
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});
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};
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};
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}
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