Add Nix derivation to build project

default.nix

@@ -0,0 +1,14 @@
+{ mkDerivation, base, exceptions, safe, stdenv, text, transformers
+, transformers-compat, unexceptionalio
+}:
+mkDerivation {
+  pname = "errors";
+  version = "2.2.1";
+  src = ./.;
+  libraryHaskellDepends = [
+    base exceptions safe text transformers transformers-compat
+    unexceptionalio
+  ];
+  description = "Simplified error-handling";
+  license = stdenv.lib.licenses.bsd3;
+}

release.nix

@@ -0,0 +1,17 @@
+let
+  config = {
+    packageOverrides = pkgs: {
+      haskellPackages = pkgs.haskellPackages.override {
+        overrides = haskellPackagesNew: haskellPackagesOld: {
+          errors = haskellPackagesNew.callPackage ./default.nix { };
+        };
+      };
+    };
+  };
+
+  pkgs =
+    import <nixpkgs> { inherit config; };
+
+in
+  { inherit (pkgs.haskellPackages) errors;
+  }

shell.nix

@@ -0,0 +1 @@
+(import ./release.nix).errors.env