Use checkPhase instead of setuptools' test_suite

default.nix

@@ -6,5 +6,7 @@ pkgs.python3Packages.buildPythonPackage rec {
 
   src = ./.; # location of setup.py
 
-  # propagatedBuildInputs = [];
+  checkPhase = ''
+    ${pkgs.python3}/bin/python -m unittest test.run_tests
+  '';
 }

setup.py

@@ -10,9 +10,4 @@ setup(
 
     package_dir={"":"."},
     packages=["drawio2py"],
-
-    # include_package_data=True,
-    # package_data={"drawio2py": ["template.oml"]},
-
-    test_suite="test.run_tests"
 )