Move xonsh customization to an overlay

nix/home.nix

@@ -1,29 +1,14 @@
-{ config, pkgs, ... }: let
-  # Mach-nix is a toolkit for constructing custom Python environments
-  mach-nix = import (builtins.fetchGit {
-    url = "https://github.com/DavHau/mach-nix/";
-    ref = "refs/tags/3.3.0";
-  }) {
-    pkgs = pkgs;
-  };
-
-  xonsh_pyenv = mach-nix.mkPython {
-    requirements = ''
-    xontrib-fzf-widgets
-    xonsh-direnv
-    '';
-  };
-
-  xonsh_with_plugins = pkgs.xonsh.overrideAttrs (old: {
-    propagatedBuildInputs = old.propagatedBuildInputs ++ xonsh_pyenv.python.pkgs.selectPkgs xonsh_pyenv.python.pkgs;
-  });
-in
+{ config, pkgs, ... }:
 {
   # Home Manager needs a bit of information about you and the
   # paths it should manage.
   home.username = "ttm";
   home.homeDirectory = builtins.getEnv "HOME";
 
+  nixpkgs.overlays = [
+    (import ./overlays/xonsh.nix)
+  ];
+
   # This value determines the Home Manager release that your
   # configuration is compatible with. This helps avoid breakage
   # when a new Home Manager release introduces backwards
@@ -39,7 +24,9 @@ in
   # Enable integration with generic Linux OSs
   targets.genericLinux.enable = pkgs.stdenv.isLinux;
 
+
   home.packages = with pkgs; [
+    # Defined in Xonsh overlay
     xonsh_with_plugins
     # Jump to directories
     zoxide