use flake compat stuff

default.nix

@@ -1,10 +1,3 @@
-{ sources ? import ./nix/sources.nix { }, pkgs ? import sources.nixpkgs { }, ...
-}:
-let
-  naersk = pkgs.callPackage sources.naersk { };
-  gitignore = pkgs.callPackage sources.gitignore { };
-in naersk.buildPackage {
-  root = (gitignore.gitignoreSource ./.);
-  buildInputs = [ pkgs.libiconv ];
-}
-
+(import (fetchTarball https://github.com/edolstra/flake-compat/archive/master.tar.gz) {
+  src = builtins.fetchGit ./.;
+}).defaultNix

shell.nix

@@ -1,29 +1,3 @@
-{ ... }:
-let
-  sources = import ./nix/sources.nix;
-  nixpkgs = import sources.nixpkgs { };
-  niv = import sources.niv { };
-  naersk = nixpkgs.callPackage sources.naersk { };
-
-  cargo-lichking = naersk.buildPackage sources.cargo-lichking;
-in with nixpkgs;
-stdenv.mkDerivation {
-  name = "elm-forbid-import";
-  buildInputs = [
-    niv.niv
-    git
-
-    # Rust
-    cargo
-    cargo-lichking
-    rustPackages.clippy
-    rustPackages.rustfmt
-    rustc
-
-    # Benchmarking + Optimization
-    hyperfine
-
-    # Testing
-    jq
-  ];
-}
+(import (fetchTarball https://github.com/edolstra/flake-compat/archive/master.tar.gz) {
+  src = builtins.fetchGit ./.;
+}).shellNix