fix shell

Author: zimbatm

default.nix

@@ -1,4 +1,4 @@
-{ nixpkgs ? <nixpkgs>
+{ nixpkgs ? import ./nix/nixpkgs.nix
 , system ? builtins.currentSystem
 }:
 import nixpkgs {

flake.nix

@@ -13,9 +13,8 @@
       # Real developers use Linux for development :-p
       system = "x86_64-linux";
 
-      pkgs = import nixpkgs {
-        inherit system;
-        overlays = [ (import ./overlay.nix) ];
+      pkgs = import ./. {
+        inherit nixpkgs system;
       };
     in
     {

nix/nixpkgs.nix

@@ -0,0 +1,8 @@
+let
+  # nixpkgs is only used for development. Don't add it to the flake.lock.
+  gitRev = "500d695aac9ea67195812f309890a911fbc96bda";
+in
+builtins.fetchTarball {
+  url = "https://github.com/NixOS/nixpkgs/archive/${gitRev}.tar.gz";
+  sha256 = "sha256-ya3rCWKDbPWMVsh89/Z1mCJ9HFa5/DKdjcgcKkWB1xs=";
+}

shell.nix

@@ -1,7 +1,4 @@
 #!/usr/bin/env nix-build
 # Used to test the shell
-{ pkgs ? import <nixpkgs> { } }:
-let
-  mkDevShell = pkgs.callPackage ./. { };
-in
-mkDevShell.fromTOML ./devshell.toml
+{ pkgs ? import ./. { } }:
+pkgs.mkDevShell.fromTOML ./devshell.toml