diff --git a/colcon_python_setup_py/package_augmentation/python_setup_py.py b/colcon_python_setup_py/package_augmentation/python_setup_py.py
index b401440..99cb7b6 100644
--- a/colcon_python_setup_py/package_augmentation/python_setup_py.py
+++ b/colcon_python_setup_py/package_augmentation/python_setup_py.py
@@ -55,7 +55,6 @@ def augment_package(  # noqa: D102
             desc.dependencies)
 
         def getter(env):
-            nonlocal setup_py
             return get_setup_information(setup_py, env=env)
 
         desc.metadata['get_python_setup_options'] = getter
diff --git a/colcon_python_setup_py/package_identification/python_setup_py.py b/colcon_python_setup_py/package_identification/python_setup_py.py
index 466e68d..07c6898 100644
--- a/colcon_python_setup_py/package_identification/python_setup_py.py
+++ b/colcon_python_setup_py/package_identification/python_setup_py.py
@@ -6,9 +6,9 @@
 with suppress(ImportError):
     # needed before importing distutils
     # to avoid warning introduced in setuptools 49.2.0
-    import setuptools
-import distutils.core
-import os
+    import setuptools  # noqa: I100
+import distutils.core  # noqa: I100, I201, I202
+import os  # noqa: I100, I201, I202
 from pathlib import Path
 import runpy
 import subprocess
@@ -238,7 +238,6 @@ def get_setup_information(setup_py, *, env=None):
     :return: dictionary of data describing the package.
     :raise: RuntimeError if the setup script encountered an error
     """
-    global _setup_information_cache
     if env is None:
         env = os.environ
     if 'DISTUTILS_DEBUG' in env: