pythonPackages.easygui: fix build

pkgs/development/python-modules/easygui/default.nix

@@ -1,4 +1,4 @@
-{ lib, fetchPypi, buildPythonPackage }:
+{ lib, fetchPypi, buildPythonPackage, tkinter }:
 
 buildPythonPackage rec {
   pname = "easygui";
@@ -9,8 +9,18 @@ buildPythonPackage rec {
     sha256 = "073f728ca88a77b74f404446fb8ec3004945427677c5618bd00f70c1b999fef2";
   };
 
+  postPatch = ''
+    substituteInPlace setup.py --replace README.md README.txt
+  '';
+
+  propagatedBuildInputs = [
+    tkinter
+  ];
+
   doCheck = false; # No tests available
 
+  pythonImportsCheck = [ "easygui" ];
+
   meta = with lib; {
     description = "Very simple, very easy GUI programming in Python";
     homepage = "https://github.com/robertlugg/easygui";