Make development experience work

Add direnv to default build
Add xonsh-direnv package to overlay and xonsh environment
Add virtualisation options

overlays/default.nix

@@ -0,0 +1,12 @@
+self: super:
+{
+	xonsh-direnv = super.callPackage ./xonsh-direnv.nix {
+		#lib = self.lib;
+		buildPythonPackage = self.python3.pkgs.buildPythonPackage;
+		fetchPypi = self.python.pkgs.fetchPypi;
+	};
+
+	xonsh = super.xonsh.overridePythonAttrs (old: rec{
+		propagatedBuildInputs = old.propagatedBuildInputs ++ [ self.xonsh-direnv ];
+	});
+}

overlays/defeault.nix

@@ -1,6 +0,0 @@
-self: super:
-{
-	git = super.git.override {
-		meta.priority = 4;
-	};
-}

overlays/xonsh-direnv.nix

@@ -0,0 +1,20 @@
+{ lib, buildPythonPackage, fetchPypi, pkgs}:
+
+buildPythonPackage rec {
+	pname = "xonsh-direnv";
+	version = "1.5.0";
+
+	src = fetchPypi {
+		inherit pname version;
+		sha256 = "OLjtGD2lX4Yf3aHrxCWmAbSPZnf8OuVrBu0VFbsna1Y=";
+	};
+
+	meta = with lib; {
+		description = "Direnv support for Xonsh";
+		homepage = "https://github.com/74th/xonsh-direnv/";
+		license = licenses.mit;
+		maintainers = [];
+	};
+
+	doCheck = false;
+}